[HN Gopher] How the great firewall of China detects and blocks f...
       ___________________________________________________________________
        
       How the great firewall of China detects and blocks fully encrypted
       traffic [pdf]
        
       Author : mngnt
       Score  : 314 points
       Date   : 2023-06-30 07:03 UTC (15 hours ago)
        
 (HTM) web link (gfw.report)
 (TXT) w3m dump (gfw.report)
        
       | anovikov wrote:
       | I wonder what can be done about detecting data hidden within
       | video streams in a steganographic way.
        
       | Renaud wrote:
       | I remember having to deal with the early GFW about 20 years ago
       | when I was working for a company that had some employees on a
       | site in Shanghai.
       | 
       | Every morning, our colleagues in China would open their mail
       | client and it would connect to our server abroad.
       | 
       | The first person would usually be OK, but for everyone else, the
       | connection would fail.
       | 
       | At the time, almost nothing was known of the GFW and it wasn't as
       | clever as it is now. I found out that the POP connection was
       | quickly blocked after a few minutes, probably triggering some
       | slow firewall rules along the way (it seemed a bit random, so I
       | assumed the firewall setup wasn't unified).
       | 
       | Moving to POPS/SMTPS seemed to improve things for a while, but
       | the connection would still be randomly blocked.
       | 
       | What worked in the end was to use a bunch of random ports instead
       | of the well known ones to accept POP/SMTP connections on the
       | server, and we never had any issues after that, at least until we
       | changed system a couple of years later.
        
         | dizhn wrote:
         | We have a satellite office in Dubai. I know their static IP.
         | When they connect to our imap/smtp server they are coming in
         | from another IP. I never looked into it deeply but assumed
         | their connection is being diverted for inspection. (If true,
         | they would probably not be below performing industrial
         | espionage with the data they are accessing)
        
           | f4c39012 wrote:
           | I've debugged connection issues with someone in China. The
           | same person, using the same browser and at the same time,
           | showed up in the logs of two cloud apps with different IP
           | addresses. The applications were adjacent in the cloud, same
           | network config and everything. We figured there was _always_
           | redirection, and we were never seeing their  "true" IP
           | address.
           | 
           | A simpler test is to search "what is my IP" and compare the
           | values returned by different services.
        
             | aeyes wrote:
             | The IP space in China is wild, multiple ISPs use the same
             | IP ranges and some even use foreign IP space but they don't
             | route them outside of China. I wouldn't be at all surprised
             | seeing proxy setups at ISPs trying to "fix" some of this.
             | 
             | Even when we had physical machines in Chinese data centers
             | it didn't mean that our service was reachable from all
             | ISPs. In 2010 we gave up on that and just started using
             | Akamai China CDN with our servers in Europe.
        
           | proto_lambda wrote:
           | At that level, there is no reason to proxy it through a
           | different IP address. If you control the network, you can
           | just make the packets come from the original, real address.
        
             | dizhn wrote:
             | It might be something government mandated where all ISPs
             | direct mail traffic to a central location. (The largest ISP
             | is the government by the way)
        
             | H8crilA wrote:
             | It was probably written by junior devs, like most other
             | software around the world.
        
               | slt2021 wrote:
               | GFW that can inspect petabytes of traffic per second for
               | 1.4 bln population cannot be written by juniors
        
           | EGreg wrote:
           | Speaking of satellites, the ones in geosynchronous orbit, how
           | can Chinese block those?
        
             | ec109685 wrote:
             | "We will shoot your satellite if you don't block access
             | while over China".
        
               | EGreg wrote:
               | In orbit? Good luck
               | 
               | Lasers maybe?
        
               | ImPostingOnHN wrote:
               | the US has done so with a missile so basic that it's
               | named "standard missile 3"
               | 
               | most satellites will just be following an uninterrupted,
               | predictable path for most of their time
        
           | occamrazor wrote:
           | Is the IMAP/SMTP connection not encrypted?
        
             | dizhn wrote:
             | Yes they are encrypted.
        
             | philjohn wrote:
             | Doesn't matter if the government mandates MITM and forces
             | install of root certs on all clients.
        
       | ballenf wrote:
       | Would a steganographic hiding of payloads be possible and usably
       | efficient inside permissible content/protocols? Has it been
       | tried?
        
         | gruez wrote:
         | That would require mimicking an existing protocol, and as per
         | the paper that's non-trivial
         | 
         | >Houmansadr et al. [39] conclude that mimicking a protocol is
         | fundamentally flawed and suggest that tunneling through allowed
         | protocols be a more censorship-resistant approach. Frolov and
         | Wustrow [35] demonstrate that even when a tunneling approach is
         | used, it still requires effort to perfectly align protocol
         | fingerprints with popular implementations, in order to avoid
         | blocking by protocol fingerprints. For instance, in 2012, China
         | and Ethiopia deployed deep packet inspection to detect Tor
         | traffic by its uncommon ciphersuits [44, 55, 67]. Censorship
         | middlebox vendors have previously identified and blocked meek
         | [29] traffic based on its TLS fingerprint and SNI value [28].
        
       | password4321 wrote:
       | https://en.wikipedia.org/wiki/Domain_fronting was a workaround
       | for a while.
       | 
       | https://signal.org/blog/looking-back-on-the-front/ (2018)
       | https://news.ycombinator.com/item?id=16970199
        
       | apatheticonion wrote:
       | Given HTTPS traffic is mostly permitted, could one obfuscate VPN
       | traffic over http/3 (which I believe is UDP)?
        
         | trallnag wrote:
         | Could China implement a MitM proxy for HTTPS traffic like many
         | companies do?
        
           | nikanj wrote:
           | No.
           | 
           | Companies get around ssl issues by minting their own root CAs
           | and configuring their workstations to trust them. China has
           | no (technical) way of forcing you to trust their root CA
        
             | gruez wrote:
             | >China has no (technical) way of forcing you to trust their
             | root CA
             | 
             | That might be true, but "install our root CA or you can't
             | access websites" would get most people to do it.
        
         | netheril96 wrote:
         | Indeed a whole class of GFW bypassing tools are now based on
         | masquerading as HTTPS. Trojan (TCP only), Vision (TCP only),
         | Hysteria (UDP), just for some examples.
        
       | Ballas wrote:
       | Seems like UDP is completely exempt, which would allow UDP-based
       | VPNs, like Wireguard through.
       | 
       | SSH is also exempt...
        
         | sysstemlord wrote:
         | I'd go for ssh if I was trying to bypass it. At least legally I
         | can claim that I'm just sshing to my aws server and not be
         | jailed for using vpn.
        
           | blablablub wrote:
           | using ssh for proxying is getting blocked within the first
           | minute.
        
             | lsllc wrote:
             | Could be a use case for X-Windows with ssh -X [0]? (so your
             | web browser is actually running outside the GFW, it's just
             | the window updates that are coming over the SSH tunnel).
             | 
             | [0] https://unix.stackexchange.com/questions/12755/how-to-
             | forwar...
        
               | blablablub wrote:
               | any ssh traffic that does not look like ssh traffic (few
               | bytes send to server, some more bytes returned) gets
               | either terminated or slowed down to a crawl
        
             | speedgoose wrote:
             | Does this mean that in addition of the classic fail2ban,
             | geoip firewall, or forever super slow login banners, we
             | could also have a honey pot sending a lot of data with a
             | traffic pattern similar than web browsing ?
        
           | yorwba wrote:
           | Trying to get off the hook on a technicality isn't going to
           | work. Lots of people use VPNs completely in the open without
           | getting jailed, because they're not otherwise of interest,
           | but if you _are_ being targeted, nobody is going to care
           | about your  "sshing to aws" excuse. And ssh tunneling web
           | traffic looks quite different from normal ssh usage anyways.
        
             | 6LLvveMx2koXfwn wrote:
             | > And ssh tunneling web traffic looks quite different from
             | normal ssh usage anyways.
             | 
             | Could you explain this further, this seems counter to my
             | understanding of encrypted traffic!
        
               | yorwba wrote:
               | SSH encryption only hides the content, not how much is
               | being sent and when. When your browser fires off a bunch
               | of requests to load a webpage, the timing is different
               | from running typical commands on a server and receiving
               | the output.
        
               | justsomehnguy wrote:
               | Open network tools in your browser and go to Reddit,
               | count total traffic. Now compare it with a typical SSH
               | session, even with 'tail -f' some logs.
        
               | praash wrote:
               | I assume the timing patterns and amounts of data would
               | likely be distinct between SSH and web. "Normal" SSH
               | usage would mostly consist of much lighter packets, such
               | as user keystrokes and terminal screenfuls of text.
               | Typing tiny commands and getting a few kilobytes of
               | output. SSH file transfers happen occasionally, sometimes
               | with a large bulk of data.
               | 
               | Active web browsing requires downloading a crapton of
               | files with wildly different sizes and sporadic timings
               | between them. Add normal user interaction, API requests,
               | ad cycles, long video streams that won't max out all
               | bandwidth, all happening at once across multiple tabs.
               | The client also sends much more data with each TLS
               | handshake and all those HTTP headers.
               | 
               | This could probably be masked by deliberately filling
               | idle periods with garbage data just to appear as a stable
               | data stream both ways.
        
               | mcpackieh wrote:
               | Forget using a real web browser over an SSH proxy. What
               | using elinks on a remote host with ssh? I bet somebody
               | using elinks across ssh is virtually indistinguishable
               | from somebody using a text editor.
               | 
               | Not much good for images or video, but you could easily
               | read https://text.npr.org/
        
           | beardog wrote:
           | I suspect TCP tunneling your traffic looks different than
           | SFTP-ing some files around.
        
           | josephcsible wrote:
           | > At least legally I can claim that I'm just sshing to my aws
           | server and not be jailed for using vpn.
           | 
           | Your mistake is assuming that China has rule of law. If
           | you're in China and you upset Xi enough, you get
           | jailed/disappeared even if you technically didn't break any
           | laws on the books.
        
         | jongjong wrote:
         | I was told that SOCKS proxies (which let you tunnel over SSH)
         | are popular in China. It's super easy to setup and you don't
         | need to install anything. You just need to SSH into any Linux
         | EC2 instance outside of your network with ssh -D $port_number
         | $username@$hostname and change a simple setting in your browser
         | to proxy through that node using SOCKS5. It's nice because you
         | still control the remote host (no need to trust some third
         | party VPN) and the traffic is encrypted between your remote
         | host and your local host (where it counts)... Anyone snooping
         | would just think that you're SSHing into your EC2 instance for
         | work purposes and not realize you're using it to browse the
         | net.
        
           | netheril96 wrote:
           | You were told wrong. If you uses SSH as a proxy, the
           | connection will be slowed down to a crawl very soon. GFW
           | distinguishes this from SSH command typing by looking at the
           | traffic. This has been in place for at least a decade.
        
         | Hikikomori wrote:
         | Went to china some years ago and my pptp vpn blocked after a
         | day. Switched to ssh and after a day it was rate limited to
         | basically nothing, but I could avoid that by switching port
         | every morning.
        
         | lordnacho wrote:
         | Why would they let that happen? Doesn't seem to make any sense
         | to me if it's how you describe it.
        
           | Ballas wrote:
           | Yes, that is why I also found it interesting. As to their
           | motives - I cannot comment.
        
         | WinstonSmith84 wrote:
         | that's mentioned at the end of Page 17. The author tells it's a
         | short term solution: "This is merely a stopgap measure, as the
         | censor can enable their censorship for UDP."
         | 
         | It doesn't seem that there are any (long term) solution to
         | bypass the rules ...
        
           | throwawayadvsec wrote:
           | steganography?
        
             | Ballas wrote:
             | Hiding the encrypted messages so that it looks like other
             | normal traffic. Like encoding your encrypted message
             | (subtly) in the pixels of an image (like noise).
        
           | reaperman wrote:
           | It does seem like this GFW scheme can be tuned to severely
           | degrade the reliability of any _unapproved high entropy_
           | traffic. However, this single scheme doesn 't cover many
           | other types of circumvention traffic, several of which are
           | noted in the beginning of the paper. This scheme primarily
           | applies to "fully encrypted" traffic - not SSL/TLS, etc.
           | 
           | So for now, circumvention can live on, but this explains to
           | everyone using fully encrypted protocols exactly why their
           | connections would have been degraded over the past couple
           | years. In the long term, steganography will probably work
           | well as long as users are able to endure much higher costs
           | for traffic (low ratio of true data to apparent data) and as
           | long as the steganographic systems are effective at hiding
           | any statistical fingerprints (very difficult). Protocol
           | mimicry is another strategy, but a paper cited in this work
           | details why successful protocol mimicry is very difficult.[0]
           | 
           | Attempts to disguise circumvention traffic as typical traffic
           | is very difficult, because a lot of fingerprinting
           | information can be gleaned from handshakes and headers. The
           | draw of fully encrypted traffic is that it provides very
           | little variation which can be used to fingerprint and
           | classify different types of usages. However, it's also easy
           | to detect and block en masse -- that much is obvious, but
           | this paper does a great job of showing how China does it and
           | inferences can be made from that to provide a view into
           | China's priorities (how much cost they're willing to incur,
           | rates of false positives they feel is acceptable). Overall,
           | China's blocking current appears to be fairly conservative
           | here, with relatively low rates of false positives.
           | 
           | In wider context, China is constantly updating their
           | detection schemes, they're quite competent at it, and
           | anything which doesn't match typical traffic is at risk.
           | 
           | 0: https://people.cs.umass.edu/~amir/papers/parrot.pdf
        
             | blablablub wrote:
             | all https traffic to servers outside of china gets slowed
             | down to a crawl after the first MB of send data.
        
         | blablablub wrote:
         | Wireguard is detected within the first minute of usage and
         | blocked. The ping is a dead giveaway.
        
           | Ballas wrote:
           | Interesting. I was just going on my limited scan through the
           | linked PDF, which evidently was not thorough enough.
        
       | DeathArrow wrote:
       | What kind of websites does China block?
        
         | throwaway2990 wrote:
         | Anything that might reveal to Chinese citizens that the CCP is
         | evil.
        
         | mooxiu wrote:
         | google, facebook, amazon, twitter, github, you name it ...
        
           | seanmcdirmid wrote:
           | Also Reddit (ironically Chinese owned).
        
             | cheaprentalyeti wrote:
             | Reddit's owned by the Chinese? I thought they were owned by
             | a US-based conglomerate called Advance Publications, which
             | is the same group that owns Conde Nast.
        
       | law_enforcement wrote:
       | The comments from people obviously never having been into a
       | restricted country are hilarious. There are a few, most likely
       | shadow approved, VPN providers that work. I refuse to believe
       | they are just smarter than the GFW. I am convinced they are
       | sanctioned and monitored. Which is fine if you never have any
       | beef with the government. Which you never know you do until you
       | do.
       | 
       | Stuff like socks5/shadowsocks and wireguard have long been
       | useless. Imagine being in your house, and you want to go out,
       | without anyone seeing you. No matter how well you try, just the
       | attempt itself reveals you are trying - thus you are caught. Same
       | for escaping GFW. A sanctioned VPN or RDP that stays alive
       | without metering, is your best option.
        
         | rfoo wrote:
         | Your comment is equally hilarious from the point of view of a
         | native who lives in China now.
         | 
         | idk if i'm smarter than the GFW but every time I rolled my own
         | censorship-circumvention tool it worked well, even the most
         | lazy way worked. I've never used any VPN provider. And FYI even
         | unchanged WireGuard still works, though there seems to be some
         | offline traffic analysis looking for that, so once a week you'd
         | wake up to your VPN connection broken and had to change
         | ListenPort on the server.
         | 
         | The only annoying thing for me is: f- you AWS, egress too damn
         | expensive!
        
           | [deleted]
        
         | bilkow wrote:
         | Can't you use a "sanctioned" VPN to tunnel your connection to a
         | "real" VPN or any wireguard endpoint? They could still be able
         | to find out you're using a VPN, but not monitor your traffic.
        
           | law_enforcement wrote:
           | Yes, you can. But you have to wonder what the sanctioned VPN
           | is doing on/to your machine. There is a lot of trust going
           | into any VPN solution.
        
             | ImPostingOnHN wrote:
             | are you talking about the VPN endpoint exploiting a 0day
             | vulnerability in the VPN client stack of the OS?
        
       | baybal2 wrote:
       | On the other hand, this shows GFW authors are more, and more
       | considerate of the collateral damage, which is a surprise. It
       | seems GFW has indeed became good enough to frustrate casual users
       | to trigger uproar when windows update, or AWS ip ranges go belly
       | up, or something.
       | 
       | VPN authors should chose the maximum collateral damage strategy
       | to frustrate GFW authors, make China as close as possible to
       | completely cutting off outside internet. No need to completely
       | evade fingerprinting, instead, do the complete opposite, and try
       | to mimic common protocols, and critical applications as much as
       | possible.
        
         | ixwt wrote:
         | From my understanding, this is what TOR did for some time. They
         | tried to make it look as close as possible to HTTPS.
        
       | H8crilA wrote:
       | The exact reverse engineered algorithm of the GFW is on page 4.
       | It looks very reasonable (given what they are trying to achieve
       | with it).
       | 
       | The easiest bypass I can think of would be to tunnel your
       | connections via TLS. For example socks server tunneled via SSH
       | which in turn is tuneled via TLS to your gateway.
       | 
       | Or perhaps you can somehow get your SSH client to transmit "GET "
       | at the beginning of the connection, have the server ignore those
       | 4 bytes, then proceed as usual.
        
         | EGreg wrote:
         | This is what I have a question about.
         | 
         | Can China pressure every domestic company to use their
         | certificate authority allowing them to decrypt all TLS traffic,
         | or be blocked? And block all sites outside China?
        
           | H8crilA wrote:
           | 1 - I believe they do it
           | 
           | 2 - they obviously do not want to block all traffic, since
           | they can do it any day, but they don't.
        
           | supriyo-biswas wrote:
           | Kazakhstan had attempted a similar move[1], albeit through
           | PSAs rather than convincing device manufacturers to add
           | certificates to end-user devices.
           | 
           | [1] https://en.wikipedia.org/wiki/Kazakhstan_man-in-the-
           | middle_a...
        
         | nikanj wrote:
         | If it's over https, an outside observer has no way of knowing
         | your stream started with a GET. Unless they've tapped ssl
         | certificates, but that would be major news
        
           | H8crilA wrote:
           | They are tapped into SSL certificates, those that are
           | generated in China. Plus wherever the Chinese intelligence
           | managed to install their "plugins".
        
             | throwaway290 wrote:
             | Are any of those tappable certificates still considered
             | trusted by wider internet? Which CAs are those? They should
             | be removed from trusted ASAP.
        
       | FredPret wrote:
       | This is such an own goal by China. All this useless work done
       | suppressing the human spirit.
        
         | pessimizer wrote:
         | > All this useless work done suppressing the human spirit.
         | 
         | It also becomes an inspiration to others.
        
           | FredPret wrote:
           | Would-be dictators, or firewall makers?
        
             | red-iron-pine wrote:
             | google
        
       | JoeAltmaier wrote:
       | So now we have to embed encrypted traffic in innocuous plaintext
       | envelopes?
       | 
       | It's like the cold war.
        
       | NamTaf wrote:
       | Interesting that it's cracking down on Shadowsocks with
       | obfuscation plugins. SS w/ v2ray was more or less the gold
       | standard when I was going there from 2017 to 2019.
       | 
       | Back then, certain times (early June, big government meetings)
       | would see a crackdown on VPNs where, so far as I could tell, they
       | just threw down crude blanket blocks on anything they sorta-kinda
       | knew was a VPN but couldn't procedurally target-block. It would
       | (usually) still connect but be rate-limited to essentially
       | nothingness.
       | 
       | I always got the vibe that they sort of informally tolerated VPNs
       | above a certain threshold of sophistication, figuring that they
       | were more interested in blocking the low-hanging fruit that the
       | unwashed masses could easily use, rather than something more
       | sophisticated that only a few techno-nerds could utilise. As
       | other posters have said, they'd know who was doing it and
       | preferred to come knocking with a rubber hose if those people
       | caused too much in the way of issues.
        
       | cookiengineer wrote:
       | But does the paper imply that something like chunked encoding
       | smuggled HTTP requests with an encrypted payload after the second
       | chunk would work?
       | 
       | That is, assuming entry nodes are available as e.g. nginx proxies
       | inside the Chinese ASNs and are allowed to operate serving
       | websites to ASNs from foreign countries.
       | 
       | I'm mentioning nginx because there were some related bypass
       | vulnerabilities in the past, and one could argue that they just
       | missed updating them.
        
         | blablablub wrote:
         | tried that...done that... blocked The last rule of the GFW is:
         | If you don't know what this traffic is or it looks suspicious,
         | block it.
        
       | olodus wrote:
       | I am a total obfuscation noob. How far does their DPI go? I am
       | guessing Tor and stuff have tried hiding it inside lots of
       | different protocols and file types (I think I read something
       | about that at some point). Is it to the point of hiding it as
       | part of a html doc (like under a specific tag or something). At
       | what point do we move towards having executable Javascript
       | generate the encrypted text which then is decrypted?
        
       | nyolfen wrote:
       | i recall a chinese guy telling me he got around it on his PC by
       | setting up a streaming webtop on a VPS on a foreign network that
       | he didn't have issues accessing
       | https://docs.linuxserver.io/images/docker-webtop
        
       | WinstonSmith84 wrote:
       | I was wondering about simply using VPNs, which is not mentioned
       | in the article at all, but checking GFW on Wikipedia, it tells:
       | 
       | > The use of VPNs in China can provide individuals access to the
       | international internet, but in China, it can be a potential legal
       | risk. In 2017, the Chinese government declared all unauthorized
       | VPN services to be illegal.[94] An example of the use of this
       | punishment is Vera Zhou, a student at the University of
       | Washington, who, when visiting her Hui parents in Xinjiang,
       | China, used a VPN to access her school homework. She was arrested
       | and sent to a Xinjiang internment camp from October 2017 until
       | March 2018, followed by house arrest after her release. She was
       | not able to return to the US until September 2019.[95][96]
        
         | noduerme wrote:
         | Just a small personal anecdote from another country with tight
         | restrictions:
         | 
         | When I rented a furnished apartment in Saigon back in 2008,
         | there was an ethernet cable on the table and a piece of paper
         | in English that said "Do not visit websites of anti-government
         | propaganda, or pornography, or news such as the New York
         | Times."
         | 
         | Naturally, as the police held my passport for the entire year I
         | was in Vietnam, I was cautious. But after a few days, I just
         | went ahead and openly browsed the NYT for a few minutes. My
         | internet was shut off for about 3 hours. The next time I did
         | it, it was shut off for 24 hours, and then I knew it wasn't a
         | glitch. It wasn't exactly immediate, either; it took a few
         | minutes. I was pretty sure there was a semi-dedicated person
         | assigned to watch my traffic.
         | 
         | That wasn't over a VPN. I wanted them to see my traffic. But I
         | knew running over a VPN would just raise suspicion. When I
         | opened up VPNs to check email after that, I did it from cafes,
         | and I did it in short spurts.
        
           | hinkley wrote:
           | In fact, the US Department of State recommends that all US
           | citizens have a photocopy of their passport with them, when
           | traveling abroad.
           | 
           | Supposedly you get in shorter lines at the consulate if you
           | have at least a photocopy of your passport available. You
           | should be able to petition the consulate of your home country
           | to issue you a new passport.
           | 
           | I think it may be illegal, but I've heard from people who
           | travel to places where it's sketchy for Americans to travel,
           | that they report their passport as destroyed, get a second
           | copy issued, then keep the first one.
           | 
           | The reasoning is that certain immigration departments see red
           | flags if they see visa stamps from certain other countries,
           | and you may get grief for having visited them. Cuba and the
           | US used to be one, but cross-border rivalries are another.
           | Knowing who hates who and presenting the right passport to
           | receive the stamp would save you grief. Also if you encounter
           | corruption/extortion you can schedule the next flight out and
           | run.
           | 
           | With the electronic ones now I don't know how many places
           | that still works.
        
             | vidarh wrote:
             | Some countries will issue second passports legally exactly
             | for the reasons you list, but you typically need to apply
             | for permission. Replacing your passport early without
             | needing to pretend it's lost because it has stamps from a
             | "problematic" country tends to be easier most places, but
             | of course a hassle if you travel to these countries more
             | than once.
        
             | noduerme wrote:
             | Anyone that says you should keep your passport on you when
             | you're in a foreign country has never traveled. I never
             | keep my passport on my person when I'm walking around
             | outside the US. I lock it away as securely as I can
             | wherever I'm staying, and carry a color copy of it in my
             | pocket.
             | 
             | Part of this is simply because American passports are
             | extremely valuable. Another part is that anyone who wants
             | to fuck with you in some semi-official capacity now has to
             | choose whether to go back to your hotel or arrest you on
             | the spot, which puts them in a better mind to give up or
             | take a bribe.
        
               | qingcharles wrote:
               | But please don't keep it in a room safe at a hotel. If I
               | had a dollar for the people I know who put valuables in
               | the room safe and lost them...
        
               | nerdbert wrote:
               | Yep, laminated color copy is the way to go.
        
               | reaperducer wrote:
               | _Another part is that anyone who wants to fuck with you
               | in some semi-official capacity now has to choose whether
               | to go back to your hotel or arrest you on the spot, which
               | puts them in a better mind to give up or take a bribe._
               | 
               | Happened to me at an airport in Thailand. Some airside
               | police officer demanded to inspect my passport, then
               | wouldn't give it back to me until I walked him to an ATM
               | so I could pay him a "tax" in cash.
               | 
               | I never went back to Thailand.
        
               | qingcharles wrote:
               | Had this in Hungary about 2004. Had no money at all at
               | the time. They handed me a notice in 15 languages which
               | said I was now permanently excluded from ever entering
               | Hungary again ^_^
        
             | reaperman wrote:
             | USA will issue "anyone" 2-3 valid passports at the same
             | time. This is designed for two reasons:
             | 
             | 1) you travel a lot and sometimes may need to mail your
             | passport off to get a pre-travel visa from some consulate,
             | while you are still outside the USA. This way you can send
             | off one passport to get the visa for your next country,
             | while keeping a valid passport with you while you're
             | abroad.
             | 
             | 2) You need to travel between Israel and countries which
             | have laws against visiting Israel (Historically, GCC
             | countries). This way you can always present whichever
             | passport doesn't have Israel's entry and exit stamps on it.
             | 
             | I've had two valid US passports at the same time, and I'm
             | just a random nobody American.
        
               | pawelos wrote:
               | Israel no longer gives you any visa stamps in passport.
               | 
               | https://www.touristisrael.com/the-israeli-passport-
               | stamp/974...
        
               | 0xffff2 wrote:
               | I visited Israel circa 2012 and this was true even then.
        
           | pdntspa wrote:
           | Wait, the police held your passport? Why?
        
             | noduerme wrote:
             | If you're an American and you rent an apartment, the local
             | police keep your passport until you leave. You keep a
             | xerox. That's how it was at the time. I don't know if
             | that's still the case.
             | 
             | I didn't feel good about it when I found out (actually, the
             | moment I signed the lease), but there was nothing I could
             | do about it.
             | 
             | My exit from Vietnam was almost humorous. I had about 50
             | DVDs in my suitcase, mostly encrypted backups and burned
             | movies, and every single one was inspected _by sight_ ,
             | holding it up to the light (to see how far the burn went?),
             | then left on the floor of the airport for me to pick up.
             | Upon re-entering the US, the customs officers did almost
             | the same thing, and then just confiscated all my discs.
             | 
             | Weirdly, no one on either side checked my laptop.
        
             | wahnfrieden wrote:
             | Police control residents, rather than provide for their
             | safety
             | 
             | Yes just like the US
        
               | mjhay wrote:
               | Ah, so just like the US then!
        
               | sixothree wrote:
               | Zip code depending of course.
        
               | mjhay wrote:
               | Good point.
        
               | noduerme wrote:
               | Actually, it's mostly down to how you address them.
        
               | noduerme wrote:
               | Police in America don't control residents. Most of the
               | time they can't even control themselves.
        
               | CamperBob2 wrote:
               | _Police in America don 't control residents._
               | 
               | How was your nap, Mr. Van Winkle? 2020 wasn't a great
               | year in the US. You were better off spending it asleep,
               | trust me.
        
               | noduerme wrote:
               | Don't flatter yourself. Nothing happened in 2020 that
               | hasn't happened a lot worse, a lot more times before in
               | America. If anything, the police were surprisingly
               | ineffectual at protecting the owners' interests. I'll
               | step out and burn a flag all day long in the street. They
               | ain't gonna arrest me.
               | 
               | I've seen the police publicly flog random people on the
               | street in Vietnam just for being in their way. What a
               | wonderfully just, equitable socialist paradise.
               | 
               | Go check out and live in a country where the police
               | actually control people and get back to me.
        
               | wahnfrieden wrote:
               | You chose a bad example
               | https://www.politico.com/story/2016/07/gop-convention-
               | flag-b...
               | 
               | Btw all you've said is something about degree of control
               | or tactics. Not relevant
        
               | vkou wrote:
               | They control unwanted residents, and unarmed[1]
               | protesters.
               | 
               | [1] They prefer not to fuck with the armed ones.
        
         | guessmyname wrote:
         | More context about this WikiPedia excerpt:
         | 
         | - https://www.chinafile.com/extensive-surveillance-china
         | 
         | -
         | https://www.rfa.org/cantonese/news/student-01272020075256.ht...
         | 
         | It looks like Zhou Yue Ming  (Vera Yueming Zhou) was sent to a
         | Chinese concentration camp mostly because she was part of a
         | religious minority and not necessarily for using a VPN to
         | access the University of Washington's website.
         | 
         | > _Vera was living in her hometown of Kuytun (Kuitun) in Ili
         | Prefecture, an area directly north of the Tian Shan mountains
         | that borders Kazakhstan. She had been trapped there since 2017,
         | when--in the middle of her junior year at the University of
         | Washington, where I was an instructor--she had taken a spur-of-
         | the-moment trip back home to see her boyfriend, a former
         | elementary school classmate. Using digital surveillance tools,
         | the Kuytun police had noticed that Vera had used a Virtual
         | Private Network in order to access websites such as her
         | university Gmail account. Given her status as a member of a
         | Muslim minority group, this could be deemed a "sign of
         | religious extremism."_
        
           | nonethewiser wrote:
           | Just tragic. Hard to imagine living in such a backwards place
        
             | wahnfrieden wrote:
             | [flagged]
        
               | b59831 wrote:
               | Same?
               | 
               | So ICE will arrest you for a VPN?
               | 
               | ICE runs concentration camps?
               | 
               | This comparison is silly.
        
           | stevofolife wrote:
           | Thanks for this elaboration. Upon reading original comment,
           | it felt very strange that she was "encamped" for using VPN to
           | access her school homework. Immediately I knew there was more
           | than it meets the eye.
        
             | fnordpiglet wrote:
             | It's subjective of course, but the real story seems worse.
        
             | psychphysic wrote:
             | The best bit is that we're enacting very similar laws in
             | the West [0]. As much as China is often deplorable I do
             | wonder how much of a blind spot we have here to our own
             | sins.
             | 
             | [0] https://news.ycombinator.com/item?id=36428046
        
           | kjs3 wrote:
           | That's the thing about "illegal but everyone does it"...it's
           | nothing to worry about until the government decides it's
           | convenient to enforce (against an individual or group), and
           | then it's definitely something to worry about and it becomes
           | a low barrier pretext for all sorts of oppression.
        
           | esaym wrote:
           | Encamped for your beliefs and not for breaking the law, that
           | makes it much better!
        
             | mannerheim wrote:
             | It's cute how people are acting as if 'ordinary people' in
             | China and foreigners don't have to worry about this. Guess
             | what'll happen to you, Mr Leaf, if Canada arrests a Chinese
             | executive and China wants a hostage? How convenient if
             | there's already a crime they can prove that you've
             | committed, too...
        
               | KptMarchewa wrote:
               | We can look at russia arresting random foreign nationals
               | for bullshit reasons right now.
        
               | jareklupinski wrote:
               | https://www.nytimes.com/article/brittney-griner-
               | russia.html
        
               | thalassophobia wrote:
               | She did commit a crime by travelling to Russia with an
               | illegal substance, for which she got roughly the same
               | sentence as a typical Russian would get if caught with a
               | similar amount of drugs. This case doesn't seem to be out
               | of the ordinary, except for the "criminal" being a famous
               | foreigner.
        
               | pindab0ter wrote:
               | Can we not call that "cute"? That seems needlessly
               | abrasive for people who are genuinely unaware.
        
               | mannerheim wrote:
               | Anyone who believes themselves exempt from the laws of a
               | country they travel to because of a little booklet they
               | carry isn't just unaware, they are foolish, and
               | dangerously so because they not only endanger themselves,
               | but everyone else they convince to adopt this attitude.
               | Better they receive the scorn they deserve now then for
               | them or anybody else to face the same consequences Griner
               | or Warmbier faced.
        
           | pessimizer wrote:
           | Exactly. This is the period when Muslim ethnic groups like
           | the Uigurs were being rounded up on any pretense to be
           | reeducated into not wanting to be separatists anymore (often
           | with no indication that they had anything to do with
           | separatism other than their ethnicity.) Seeing the VPN pop up
           | was more than enough of an excuse. Calling it a "genocide" is
           | 99% propaganda, but it was obviously a sinofication meant to
           | get rid of separatist identities and cultures, and a horrible
           | injustice. In the beginning, they were inspired and immunized
           | by the US's anti-Muslim fervor during the GWB invasions (we
           | were not only not criticizing, but probably even sharing
           | intelligence with China.)
        
             | matchapples wrote:
             | Why do you say it's 99% propaganda?
             | 
             | "sinofication" sounds a lot like "eliminating the existing
             | culture" which sounds a lot like genocide. Genocide is more
             | than just murdering everyone like in some of the most well
             | known cases like the Holocaust -- it includes elimination
             | of an ethnic group by any means possible, including
             | "nativification"
        
               | ineptech wrote:
               | I understand where you're coming from, but -cide implies
               | killing.
        
               | KptMarchewa wrote:
               | Of a nation or ethnic group.
        
               | ImPostingOnHN wrote:
               | the "cide" in genocide refers to destroying
               | 
               | for example, a cultural genocide refers to destroying
               | culture, e.g. Uighur or Muslim culture
        
               | woooooo wrote:
               | Would you say the choice of the word "genocide" here is
               | because it's the most accurate description of what's
               | going on?
               | 
               | Or is it chosen for rhetorical/propaganda effect without
               | too much concern for accuracy?
        
               | ImPostingOnHN wrote:
               | Would you say the common, accurate usage of the term
               | "cultural genocide" to refer to what the term refers to,
               | is a bigger or smaller problem than the actual cultural
               | genocide itself?
        
               | mayormcmatt wrote:
               | Not the person you're responding to, but it is an
               | accurate description of genocide under its current
               | meaning as defined by the UN (probably the most
               | authoritative body on this kind of matter).
               | 
               | https://www.un.org/en/genocideprevention/genocide.shtml
               | 
               | What the Chinese are doing there is covered under Article
               | II, c.
               | 
               | If you are being pedantic by holding fast to the literal
               | Greek translation of "geno" and "cide" then, well, this
               | is simply not the complete modern meaning of the term.
        
               | ineptech wrote:
               | There is no authoritative body on the definitions of
               | words. More generally, if genocide can mean "not
               | killling, but very bad" then it is not much use except as
               | an epithet - a negatively-loaded bomb to be lobbed in
               | partisan debates at people who you think are doing
               | something very bad. Virtually every controversial policy
               | could be described as, "Causing serious bodily or mental
               | harm to" some group.
        
               | dirtyid wrote:
               | The definition, US propaganda under Pompeo as head of
               | State tried (and failed to meet), was UN's convention on
               | genocide, which would trigger legal responses on member
               | states. The TLDR is Pompeo laundered very tortured legal
               | analysis through Zenz and some Gulanist Saudi think tank
               | (IIRC) to try insinuate PRC met the definition when most
               | credible international lawyers saw through the bullshit,
               | but noted PRC actions closer to cultural genocide, which
               | does NOT have definition at UN, and hence not
               | prosecutable. The result is PRC actions merely labelled
               | as potential human rights abuses at UN, aka business as
               | usual, and a bunch of useful idiots who ate Pompeo's bait
               | thinking PRC actually met the definition of genocide when
               | it manifestly did not. And buy business as usual, of
               | human rights abuses / cultural genocide, it puts PRC XJ
               | actions in league with behaviours of the west. Hence you
               | don't hear much about the XJ campaign anymore from
               | western propaganda, because the propaganda was mostly
               | useful if the genocide label stuck at UN, and made PRC
               | actions more nefarious not equal to west. Now it's mostly
               | used by US to justify XJ sanctions and trying to partners
               | onboard to cripple XJ industry like solar, cotton,
               | agriculture.
        
               | dirtyid wrote:
               | It's absolutely not. There's a reason US propaganda under
               | Pompeo had to manufacture and launder reports with
               | tortured legal interpretation to try to get the genocide
               | label to stick but couldn't because there's no intent to
               | destroy, hence useful idiots trying to be pedantic and
               | argue how enforcing family planning reflect intention
               | even though that applied to Han majority, or mass
               | (temporary) internment / inflicting "pain" somehow
               | equivalent to physical destruction while population
               | continues to grow.
               | 
               | Modern definition of genocide at UN explicitly wouldn't
               | categorize what PRC is doing in XJ - cultural genocide -
               | because members, especially west went out of their way to
               | ensure cultural genocide would have little legal
               | ramifications, otherwise Canada would have been
               | sanctioned to death for self professed cultural genocide
               | a few years ago. Incidentally the entire reason Pompeo
               | tried to propagandize genocide label was because it would
               | trigger diplomatic ramifications at UN. What the PRC is
               | doing in XJ is cultural genocide, and bluntly that's
               | permissible thanks to lobbying from the west.
               | 
               | The entire manufactured genocide narrative is so retarded
               | because if PRC wanted to, they could just... commit
               | genocide. At PRC scale they can wipe out the 12M Uyghurs
               | in a few weekends on the cheap instead of wasting
               | trillions of RMB trying to sinicize them.
        
               | woooooo wrote:
               | That article IIc pivots on the key phrase "physical
               | destruction".
               | 
               | Look, internment isnt good either, why dig in your heels
               | on the most loaded possible word?
        
               | ImPostingOnHN wrote:
               | physical destruction, internment, cultural genocide, they
               | are all happening
               | 
               | why not focus on that, rather than your personal,
               | individual dislike of a term?
               | 
               | why dig your heels in on the semantics of the thing,
               | rather than the substance?
        
               | last_responder wrote:
               | " but -cide implies killing."
               | 
               | Maybe to simple minded uneducated people. Others take the
               | time to learn the actual definition.
        
               | jxramos wrote:
               | what?
               | 
               | > cidium "act of killing," from caedere "to kill, to cut
               | down" (from PIE root *kae-id- "to strike").
               | https://www.etymonline.com/search?q=homocide
               | https://www.etymonline.com/search?q=fratricide
               | https://www.etymonline.com/search?q=suicide
               | 
               | lots of others
        
               | mistermann wrote:
               | > Why do you say it's 99% propaganda?
               | 
               | I suspect because of propaganda.
        
             | l3mure wrote:
             | > In the beginning, they were inspired and immunized by the
             | US's anti-Muslim fervor during the GWB invasions (we were
             | not only not criticizing, but probably even sharing
             | intelligence with China.)
             | 
             | Yeah, seems to be overlooked quite a lot since it's
             | convenient for the US narrative lately.
             | 
             | > Starting in 2002, the American government detained 22
             | Uyghurs in the Guantanamo Bay detainment camp. The last 3
             | Uyghur detainees, Yusef Abbas, Hajiakbar Abdulghupur and
             | Saidullah Khalik, were released from Guantanamo on December
             | 29, 2013, and later transferred to Slovakia.
             | 
             | > None of the Uyghurs wanted to be returned to China. The
             | United States declined to grant the Uyghurs political
             | asylum, or to allow them parole, or even freedom on the
             | Naval Base.
             | 
             | > A May 2008 report by the Inspector General of the United
             | States Department of Justice claimed that American military
             | interrogators appeared to have collaborated with visiting
             | Chinese officials at Guantanamo Bay to enact sleep
             | deprivation of the Uyghur detainees.
             | 
             | https://en.wikipedia.org/wiki/Uyghur_detainees_at_Guantanam
             | o...
        
         | Arn_Thor wrote:
         | And for those who don't feel in legal jeopardy many VPNs are
         | still being blocked and reconfigured in an endless arms race
         | between the provider and the GFW
        
         | FaultBit wrote:
         | A lot of people actually use VPNs in China (since 2010 even),
         | and some of them call it "Jia Su Qi " which basically means
         | "booster" (for your internet). Some use it for lower latencies
         | when playing foreign games. The issue is that VPN connections
         | get easily blocked. We aren't really worried about legal
         | issues.
         | 
         | Except for that one time when police (of a certain district,
         | not everywhere in China) knocked on people's doors to inspect
         | their phones for VPNs during the "white paper protest" I
         | believe.
        
           | seanmcdirmid wrote:
           | Surely Xinjiang has stricter rules and more aggressive
           | enforcement than the other provinces/regions? They always put
           | a hardliner in as party head.
        
         | helen___keller wrote:
         | When I was in China in 2019, the VPN built into google fi
         | actually got me around the GFW with zero effort. I didn't even
         | realize it until I caught myself checking American social media
         | unhindered.
         | 
         | My experience is most younger and tech savvy people have a VPN.
         | It's common / casual, like speeding your car by 10mph on the
         | highway.
         | 
         | Most people are not persecuted for using a VPN, I assume that's
         | reserved for people who the government already wanted to
         | persecute and just need to give an excuse for why they detained
         | their target.
        
           | chanind wrote:
           | The reverse is true as well. I traveled in India with a
           | friend from China who used their Chinese sim card in India,
           | and their data was censored through the firewall. Really
           | annoying to be outside China and not able to use Google maps.
        
           | computerfriend wrote:
           | That's roaming, not a VPN.
        
             | ktta wrote:
             | Google Fi offers a VPN as well:
             | https://support.google.com/fi/answer/9040000?hl=en
        
           | ehhthing wrote:
           | Assuming what you mean is over mobile data (and not over
           | wifi), mobile data works differently than typical internet.
           | You can think of it like when you connect to a mobile network
           | what you're actually doing is making an IPsec connection to
           | your carrier, with all data flowing over that IPsec
           | connection. As such any carrier with a roaming agreement in
           | China will bypass the GFW entirely -- and this is by design,
           | Chinese carriers have to whitelist the APNs of western
           | companies they do business with.
        
           | qingcharles wrote:
           | This is the same in Qatar, and probably in other Middle-East
           | countries. Most of the residents use a VPN to get around the
           | firewall, but I don't think anyone would be prosecuted for it
           | unless the police wanted a nice easy reason to get you into
           | custody.
        
           | synergy20 wrote:
           | That's because the GFW allowed it, GFW has no problems to
           | block any VPN at will.
           | 
           | GFW is sophisticated beyond imagination, one way to detect
           | VPN traffic(or SSL, or SSH) is to observe its patterns and
           | where the traffic is going. It's not too hard to have a
           | blacklist of all VPN vendors too.
           | 
           | shadowsocks was designed to bypass it(to make traffic looking
           | random), I recall its developers were visited by cops and
           | warned to stop doing that.
           | 
           | It's said China built the largest LAN on earth, the
           | government is just too scared by its people to get educated,
           | it's a true parallel universe.
        
           | pantalaimon wrote:
           | I think China doesn't care if foreigners use a VPN, it's
           | their own people they want to keep under control.
        
             | balder1991 wrote:
             | I keep contact with a girl in China and from her reports
             | using VPNs is kinda common for young people with college
             | education. She would do it sometimes to access YouTube, and
             | would laugh it off when I would say she should be careful
             | doing such things.
             | 
             | I suppose for the government, as long as it isn't the
             | majority of people doing something that would cause
             | trouble, it isn't worth tracking down all things, as
             | expected.
        
               | mrguyorama wrote:
               | This is intentional; "Oh it's not authoritarian/bad,
               | people use VPNs all the time and get away with it".
               | 
               | Except for that muslim chick another commenter pointed
               | out, or anyone else the party decides is undesirable.
        
             | mannerheim wrote:
             | Just be prepared to spend a year or two in prison if
             | relations between your country and China worsen and they
             | need a hostage.
        
             | [deleted]
        
         | thaumasiotes wrote:
         | > The use of VPNs in China can provide individuals access to
         | the international internet, but in China, it can be a potential
         | legal risk. In 2017, the Chinese government declared all
         | unauthorized VPN services to be illegal. An example of the use
         | of this punishment is Vera Zhou, a student at the University of
         | Washington, who, when visiting her Hui parents in Xinjiang,
         | China, used a VPN to access her school homework. She was
         | arrested and sent to a Xinjiang internment camp from October
         | 2017 until March 2018, followed by house arrest after her
         | release. She was not able to return to the US until September
         | 2019.
         | 
         | Use of VPNs is... universal... among middle-to-upper-class
         | Chinese. This is obviously not an example of legal risk
         | associated with _using a VPN_. Rather, it 's an example of a
         | punishment coming down on someone who was targeted for other
         | reasons.
         | 
         | An immediate implication is that, if you repealed all the laws
         | against VPNs, nothing about anything would change.
        
       | beebmam wrote:
       | Deeply unethical stuff. Why are Chinese people not currently
       | trying to overthrow this garbage?
        
         | edvards wrote:
         | Pragmatism, I suppose. The country does well enough
         | economically for people to accept it, not to mention they're
         | used to it all already.
        
         | mrguyorama wrote:
         | Because "Everybody does it and gets away with it", as seen in
         | this very comment section, so it doesn't actually put much
         | pressure on the public as far as they are concerned.
         | 
         | Also, "it's done for social harmony"; Very few places are as
         | dogmatically hostile towards social good as the US, and are
         | willing to make individual liberty sacrifices so that everyone
         | may be better off. Arguably this is the same rhetoric or
         | philosophy as the "Thin blue line" American cops love.
         | 
         | Also, your average chinese person just doesn't care to see
         | english language media that much. They have diverse (to them)
         | opinions and culture on their homegrown social media systems,
         | and don't feel a need to leave the walled garden of Chinese
         | internet much in the same way most westerners do not feel the
         | need to join Russia's social media apps.
         | 
         | Also, the CCP "brought millions out of poverty" within living
         | memory. Many people there feel that justifies a hell of a lot
         | of vaguely "bad" actions, or makes it way easier to rationalize
         | things.
        
         | gruez wrote:
         | The threat of you and your family members getting sent to a
         | labor camp is a good incentive.
        
       | j-a-a-p wrote:
       | With Youtube blocked, the Chinese are not being bombarded with
       | VPN advertisements
        
       | jiggywiggy wrote:
       | Yeah already 10-12 years ago was clear.
       | 
       | My university vpn only worked for a few days while studying in
       | China.
       | 
       | But there is this tiny little vpn software being spread around.
       | Not sure if it's true but I remember it's falun gong teaming up
       | with the CIA. Which at the time was able to go undetected, I
       | think they keep rotating the IPS or something.
       | 
       | Was interesting how fast that tool spread "offline" between
       | international students. Also Chinese have it but its less known
       | among them.
       | 
       | Not sure if it still
       | works:https://en.m.wikipedia.org/wiki/Freegate
       | 
       | [Edit] Here is an old hn comment saying it doesn't work anymore
       | and other options that are also hard;
       | 
       | https://news.ycombinator.com/item?id=10101965
        
         | LT_SPA wrote:
         | Nearly the same experience with my campus life.
        
       | cynicalsecurity wrote:
       | Can you bring a Starlink and then just don't really care?
        
         | hughesjj wrote:
         | Nope. Starlink shuts down over china on the satellite side.
         | Tesla has a huge presence there and they also threatened to
         | shoot the satellites down (which they've done before) if
         | starlink provided internet access there
        
           | reaperman wrote:
           | To clarify for readers: China has never shot down someone
           | else's satellite. They've only destroyed one satellite ever
           | and it was their own.
        
             | red-iron-pine wrote:
             | and creating a ton of space debris in the process. oups
        
         | RocketMan9999 wrote:
         | Maybe you can, but the Chinese "VPN law" used some wording like
         | "unauthorized communication channels" without further
         | definition. They can just call Starlinks "unauthorized" and
         | start confiscating them, just like what they did to the
         | satellite dishes for receiving foreign TV signals.
        
       | ck2 wrote:
       | How long do you figure until the first public execution for using
       | starlink?
       | 
       | And yet we can never cut them off because it would be economic
       | suicide.
        
       | maldev wrote:
       | This paper is nice, but it goes over some finer technical things.
       | So, not about the great wall, but there's projects out there,
       | like this one https://github.com/salesforce/ja3 , which talk
       | about how you can fingerprint fully encrypted traffic(TLS/HTPS).
       | There's a great section in the Readme "How it works" that goes
       | over it. Would be surprising if the great wall doesn't do this,
       | when some open source firewall will.
        
         | supriyo-biswas wrote:
         | Chrome randomizes the ClientHello these days[1], so JA3 is
         | obsolete in that sense. You could still build a fingerprint off
         | of the common advertised TLS parameters, disregarding their
         | order. The linked paper references an incident where the list
         | of ciphersuites were used to detect Tor-obfs connections[2][3].
         | 
         | [1] https://www.fastly.com/blog/a-first-look-at-chromes-tls-
         | clie...
         | 
         | [2] https://gitlab.torproject.org/legacy/trac/-/issues/4744
         | 
         | [3] https://blog.torproject.org/ethiopia-introduces-deep-
         | packet-...
        
           | [deleted]
        
       | mensetmanusman wrote:
       | China doesn't realize how much they are being held back by
       | meaningless investments of time and expertise on this. They spend
       | almost the same %GDP as the US does on the US military as on
       | their internal suppression forces.
       | 
       | Maybe it's good for the world that they burn so much talent and
       | wealth on adding inefficiency to their internal information
       | exchange.
        
         | Herring wrote:
         | I wouldn't be so sure that it's a bad idea. Look how social
         | media has damaged democracy around the world. US democracy is
         | stuck in a bit of a death spiral -
         | https://www.theatlantic.com/ideas/archive/2021/04/how-
         | stop-m.... I hate repression, but they've been at it for
         | thousands of years and I'm no longer super confident we have
         | something better (see citizens united, roe v wade, affirmative
         | action). China's life expectancy just beat the US.
        
           | ed25519FUUU wrote:
           | Free speech causing problems for the USA yet again?
        
             | Herring wrote:
             | I'd say the issue is "factionalism" as the US founding
             | fathers identified it. Some group (elites, landlords,
             | corporations, white people, etc) is looking out only for
             | themselves at the expense of society in general. East Asian
             | countries love enforcing their conformity and harmony.
        
           | nonethewiser wrote:
           | You outed your poor judgement with the endorsement of racist
           | admissions practices.
        
           | nirimda wrote:
           | The US doesn't have a minority rule death spiral because of
           | social media, it has a minority rule cycle because the
           | constitution literally entrenches minority rule via
           | mechanisms like senatorial malapportionment, supermajorities,
           | the electoral college and judicial review of policy (see
           | citizens united, roe v wade, affirmative action) rather than
           | merely procedure. It has experienced this before, sometimes
           | devolving into outright civil war, without actually reaching
           | death.
           | 
           | The technologies for resolving America's problems are well
           | understood - majority decision making, parliamentarism,
           | representation and participation of electoral minorities
           | rather than inhibiting the work of the majority, a narrower
           | scope of judicial review and/or a more flexible constitution.
           | But as long as people say, as you do, "it isn't the thing
           | that caused the problem that is the problem, it is some fancy
           | gadget that is the problem", then you will be unable to solve
           | the problems
        
             | pessimizer wrote:
             | > It has experienced this before, sometimes devolving into
             | outright civil war, without actually reaching death.
             | 
             | That's not really enough to establish a pattern, though.
             | People in China have furniture older than the United
             | States.
             | 
             | > But as long as people say, as you do, "it isn't the thing
             | that caused the problem that is the problem, it is some
             | fancy gadget that is the problem", then you will be unable
             | to solve the problems
             | 
             | This is victim blaming. US citizens get no say in
             | governance:
             | 
             |  _" Testing Theories of American Politics: Elites, Interest
             | Groups, and Average Citizens"_
             | 
             | https://www.cambridge.org/core/journals/perspectives-on-
             | poli...
        
         | dirtyid wrote:
         | PRC centralized narrative setting apparatus is more efficient
         | than constant misinformation shitshow on western platforms. Not
         | to mention the entire reason why PRC has domestic info
         | ecosystem is because they were prescient in filtering external
         | content. The system already paid for itself many times over.
         | 
         | >They spend almost the same %GDP as the US does on the US
         | military as on their internal suppression forces.
         | 
         | It's almost as if PRC doesn't spend that much %GDP on military.
         | The waste is PRC spending as much as US on domestic policing,
         | which is not great considering how militarized US policing is.
         | Meanwhile PRC simply doesn't spend that much on defense <2% vs
         | US ~3.5%, if you include guestimates of shadow budgets, 3% vs
         | 6%.
        
         | jcarrano wrote:
         | It is not the goal of the CCP to advance China as it is to keep
         | themselves in power.
        
           | H8crilA wrote:
           | I would disagree. The leading organization is much more
           | aligned with the needs of the nation than the likes of Iran
           | or Russia, which probably wouldn't mind bombing the shit out
           | of their own city if it was necessary to stay in power.
           | 
           | For example they actually bow to American pressure and try to
           | avoid sanctions or other trade problems. As of today their
           | navy could be completely destroyed with like 30% of the US
           | Navy, so any naval blockade is probably unbreakable for them.
           | Iran's hunta would (and did) just say "whatever" and
           | continued tanking the GDP.
           | 
           | Another example - the Chinese intelligence helps domestic
           | industries, even those that are far from the defense
           | business.
        
             | nonethewiser wrote:
             | > which probably wouldn't mind bombing the shit out of
             | their own city if it was necessary to stay in power
             | 
             | See the Tiananmen Square Massacre.
        
               | H8crilA wrote:
               | Bombing a city can result in tens to hundreds of
               | thousands of casualties.
        
               | pessimizer wrote:
               | You have to have a sense of proportion on this, and an
               | example that isn't 30 years old.
        
               | mensetmanusman wrote:
               | They fear bomb their own cities though (using drones!):
               | 
               | Shanghai Residents Told to 'Control Your Thirst for
               | Freedom' Amid Lockdown
               | 
               | https://www.newsweek.com/shanghai-residents-told-control-
               | you...
        
             | throwaway290 wrote:
             | I didn't downvote you but if a government
             | 
             | - offers no way of replacing itself democratically
             | 
             | - extends own term indefinitely
             | 
             | - blocks free exchange of information
             | 
             | - censors specific speech that shows its failures or desire
             | of people to replace it
             | 
             | - suppresses internal protests with murders and
             | disappearings of people (1989 Tiananmen, 2019+ Hong Kong,
             | blank paper movement, ...)
             | 
             | etc then it's super clear its primary goal is maintaining
             | power.
             | 
             | Sure, it cannot maintain power without at least seeming to
             | be "aligned with nation". But it takes second place to
             | maintaining power.
        
               | justincredible wrote:
               | [dead]
        
               | pessimizer wrote:
               | There's probably more disagreement within the Chinese
               | government than between the two dominant parties of each
               | of the western powers.
        
               | red-iron-pine wrote:
               | Perhaps, but you wouldn't know it, and the results sure
               | aren't felt domestically or internationally.
        
             | pdntspa wrote:
             | You have to keep the poeple happy enough, not even China
             | could withstand the full force of their own people rising
             | up against them.
             | 
             | So, on the surface, you appear aligned with growth and
             | advancement and all that.
             | 
             | But under the surface, the system is about control, and
             | only control.
        
         | bitwize wrote:
         | Get used to it; we will soon be a part of China's "community of
         | common destiny".
        
           | nonethewiser wrote:
           | I wouldn't say that. But Western countries would absolutely
           | replicate the surveillance and censorship if they could. And
           | they do in some ways, but there are many structural things
           | stopping them.
        
             | m-p-3 wrote:
             | They let the private sector do it for them instead.
        
       | mdhb wrote:
       | Limited use cases but for moving info in and out of a system like
       | this you should be able to use this
       | https://en.m.wikipedia.org/wiki/Chaffing_and_winnowing
        
         | noman-land wrote:
         | This is a really cool idea. Thanks for sharing.
        
       | JPLeRouzic wrote:
       | The algorithm found seems so unintuitive that I wonder if it was
       | not found by the AI.
       | 
       | " _Allow a connection to continue if the first TCP payload (pkt)
       | sent by the client satisfies any of the following exemptions:
       | 
       | Ex1: popcount(pkt) len(pkt) <= 3.4 or popcount(pkt) len(pkt) >=
       | 4.6.
       | 
       | Ex2: The first six (or more) bytes of pkt are [0x20,0x7e].
       | 
       | Ex3: More than 50% of pkt's bytes are [0x20,0x7e].
       | 
       | Ex4: More than 20 contiguous bytes of pkt are [0x20,0x7e].
       | 
       | Ex5: It matches the protocol fingerprint for TLS or HTTP.
       | 
       | Block if none of the above hold._"
        
         | vbezhenar wrote:
         | This is just some experimentation results, it's not algorithm.
        
           | amrocha wrote:
           | An algorithm is just a bunch of rules to follow to perform an
           | operation, so this looks like an algorithm to me.
        
             | netheril96 wrote:
             | You misunderstood your parent comment. What he/she meant is
             | that the "algorithm" is only a guess from reverse
             | engineering. The actual algorithm deployed at GFW can look
             | significantly different.
        
         | colanderman wrote:
         | Ex1 is just excepting low-entropy packets (distribution of 1s
         | and 0s tends toward the mean for high-entropy data). Encrypted
         | data presents as high-entropy. This is a crude method (errs on
         | the side of not excepting) but is very efficient for embedded
         | hardware to compute.
         | 
         | Ex2-4 are just excepting ASCII text, which is used by many
         | unencrypted protocols (e.g. IMAP), but which are high enough
         | entropy that they statistically will fail the first test often.
         | 
         | Ex5 is necessary because TLS is high-entropy (by nature of
         | being encrypted). HTTP is also excepted presumably so e.g.
         | compressed uploads (e.g. images/video) aren't flagged.
         | 
         | That "low entropy" is the key to bypassing the GFW isn't
         | surprising at all -- high entropy is all but a necessary
         | feature of most cryptography schemes. (I say "all but" because
         | -- encryption isn't adding information, so unless you compress
         | before you encrypt, it's possible for a (hypothetical)
         | encryption scheme to preserve entropy, according to several
         | objective metrics. I don't know of any that do this, beside the
         | meta scheme of compression before encrypting, followed by
         | steganographically padding the encrypted data afterward. This
         | of course leaks some information through the encryption --
         | equal to the negentropy of the message -- but it would
         | typically be information that can't be gleaned from context,
         | e.g. that the message is HTML+text.)
         | 
         | So... base64-encode your TLS?
        
         | tgv wrote:
         | Looks more like it was found using random forests.
        
           | H8crilA wrote:
           | Lol you guys never worked with real data :D
           | 
           | There's at least 1'000 such algorithms at each google-like
           | company.
        
         | reaperman wrote:
         | > I wonder if it was not found by the AI.
         | 
         | Do you mean "found" by the CCP, or "found" by the researchers?
         | In the case of the CCP it was likely generated through basic
         | statistical analysis, and tuned to minimize side effects and
         | collateral damage below some threshold of acceptability (~0.6%
         | of global traffic unintentionally blocked). In the case of the
         | researchers, the paper details the basic statistical analysis
         | used to discover these rules.
        
         | H8crilA wrote:
         | It's extremely intuitive. You're trying to filter unusual,
         | encrypted traffic.
         | 
         | First rule exploits the IND-CPA property of most encryption.
         | You want to kill traffic that has about 4 bits set to 1 per
         | byte, i.e. traffic that "looks random".
         | 
         | The following rules are exemptions for permissible encrypted or
         | compressed traffic (note that compression, while not IND-CPA,
         | results in high entropy and thus will trigger the first rule).
         | 
         | This could work very well, which is confirmed by the
         | researchers in this paper.
        
           | JPLeRouzic wrote:
           | Thanks for the information, it is very interesting.
        
           | nerdbert wrote:
           | Cool, I'll just base32 my encrypted traffic and sail through!
        
         | delfinom wrote:
         | That looks hilariously easy to defeat though it will require
         | introducing "0x20,0x7e" padding to protocols heh.
        
       | GartzenDeHaes wrote:
       | > 1 security vendor flagged this URL as malicious
       | 
       | https://www.virustotal.com/gui/url/f530591ff939e09c1cf8bc534...
        
       | seanmcdirmid wrote:
       | I mentioned this a few years ago (maybe 7-8 years ago) on HN when
       | I was told everyone just uses a VPN. Even back then, the cat and
       | mouse game was annoying. You would purchase a VPN (plenty
       | offered), pay a year subscription, and then it would go dark a
       | couple of weeks later (sort of like a membership at a gym that
       | closes down a week after you renew a year subscription). I gave
       | up quickly on outside access, though we had a line out at work so
       | it wasn't that bad.
        
       | __sy__ wrote:
       | I've done so much experimentation with GFW pre pandemic while
       | staying in China for extended period of times. I was always
       | amazed at how quickly they would catch up on my shadowsocks,
       | random ssh tunnels...etc. 48 hours top before I had to rotate
       | IPs. This report seems to indicate this is now instant?
       | 
       | Fwiw My most reliable trick ended up piggie-backing off of a
       | physical line going into Hong Kong from Shenzhen, and when
       | roaming around China, using a vpn to get to that shenzhen
       | gateway. As far as I can recall, that always worked. This led me
       | to believe that most of the vpn traffic analysis (and
       | blocking)was done at the edge of the GFW and not inside of it.
       | Again, this could be outdated by now.
        
         | ehhthing wrote:
         | GFW only looks at connections with destination IPs outside of
         | China, the private fibre line bypasses it entirely.
        
           | traceroute66 wrote:
           | > the private fibre line bypasses it entirely
           | 
           | Well, I'm sure the Chinese are tapping it. ;-)
           | 
           | Its more that they are just not actively acting on the
           | content.
        
             | ethbr0 wrote:
             | Not much use tapping encrypted packets, which is why it
             | terminates connections when able.
        
         | EGreg wrote:
         | Why don't they just detect and block all VPNs? In Dubai, that's
         | what seemed to be happening
        
         | jszymborski wrote:
         | I wonder if the whole tor obsf4 and snowflake business works
         | with the GFW.
        
           | rfoo wrote:
           | Yes but they are unfortunately targeted more than other
           | censorship circumvention tools. Since everyone knows
           | Tor/Obfs4/Snowflake it's easier to get your research
           | published if you work on detecting that.
        
         | gruez wrote:
         | There's a more straightforward way: roam with a foreign sim
         | card. Roaming traffic is tunneled to your home telco and for
         | whatever reason the tunnel isn't inspected at all. With the
         | advent of esims you can buy a roaming sim and use it on your
         | phone within minutes.
        
           | Roark66 wrote:
           | Can you activate it while abroad though? After I moved away
           | from the UK I still had to have a UK mobile phone for various
           | things. My UK sim would stop working after about a year away.
           | When buying a new one I had to get someone in UK to put it in
           | their phone to let it at least once connect to the home
           | network. Without it the card would be useless. Is using
           | foreign sim cards now easier?
        
             | gruez wrote:
             | There are esims explicitly targeted to travelers. Those are
             | the ones you want. In my experience they don't have any
             | activation restrictions like the ones you describe
        
             | kotaKat wrote:
             | eSIMs just need a data connection back to the SM-DP server
             | and that can be done over Wi-Fi. I don't _think_ that
             | protocol is blocked that they talk to it, and the SM-DP
             | vendors on the market are typically  "global" providers
             | that work with multiple operators.
             | 
             | EDIT: I checked myself to be sure. It's "RAM over HTTP(s)"
             | -- "Remote Application Management" of the eSIM. GFW doesn't
             | block HTTPS, so you should be able to get provisioned to
             | any carrier worldwide while inside the firewall.
             | 
             | https://www.sharetechnote.com/html/Handbook_LTE_eSIM.html
        
         | narism wrote:
         | MS and other vendors recommend doing something similar
         | (connecting via Hong Kong): https://learn.microsoft.com/en-
         | us/azure/virtual-wan/intercon...
        
         | gaoshan wrote:
         | Many years back I was running a socks proxy for access while in
         | China and I found that it worked great in Shanghai but was
         | rapidly blocked (or degraded in some fashion) in Hangzhou. That
         | seemed internal and not edge but I do no really know how they
         | were interfering with it. Given Hangzhou's tech expertise it
         | just may be the ISP there was more capable and up to date?
        
           | kccqzy wrote:
           | Was there an international event in Shanghai at that time? If
           | they expected a large number of foreigners in a particular
           | region they would relax the censorship in that particular
           | region. They could even do it per hotel room where hotel
           | rooms booked by foreigners automatically have lesser
           | interference between GFW.
        
             | gaoshan wrote:
             | That might be it. I was there every year for about a 15
             | year period but this may have been around the time of the
             | 2010 Expo. Though I was not in hotels, I was in apartments
             | (ones owned and lived in by Chinese, not foreigners).
        
         | apatheticonion wrote:
         | I tried to setup a shadowsocks server to bypass the GFW about 2
         | weeks ago. Server was hosted on my local network in Australia
         | (with public IP), client was connecting from China (using the
         | server IP).
         | 
         | It was blocked immediately and the client could not connect. I
         | had several unknown IPs try to connect prior to the attempted
         | connection.
         | 
         | I was stunned at how water tight the GFW is, it's really
         | unfortunate as I would love to work/travel through China but
         | cannot due to needing an active internet connection.
        
           | m-p-3 wrote:
           | I run https://snowflake.torproject.org/ in my browser as my
           | way to help.
        
           | __sy__ wrote:
           | Yeah pdf of report says that blocking is instant as of 2021.
           | Also completely agree with the need for an active connection
           | to do work. A lot of the software/hacker devs I knew have
           | left China all together in the last 3-4 years. Inability to
           | look up stuff reliably (even on working VPN providers) was
           | one of the reasons cited by a few.
        
           | Grimburger wrote:
           | That's a massive shame because shadowsocks has been the only
           | real reliable method for a long time.
           | 
           | I used it successfully when I was in mainland China while
           | VPN's, even the ones boasting they could get through the GFW
           | were all hit or miss.
        
           | throw_19cn1k3 wrote:
           | A fellow Aussie currently in China, a Trojan [0] server has
           | been working fine for the last week I've been here. I've got
           | it hosted through a VPS (smaller provider) in LA. While it's
           | a bit of a pain to setup, reliability has been pretty decent
           | (with occasional? short breaks) and definitely useable - my
           | laptop is connected 24/7 and I can access the unfiltered web,
           | including video, just fine. V2ray also supposedly works quite
           | well, but I haven't looked into it.
           | 
           | [0] https://github.com/trojan-gfw/trojan
        
           | fundatus wrote:
           | Last time I went to China (2018) you could simply get a China
           | Unicom Hong Kong SIM card and then use that to roam in
           | mainland China. With that you'd get the Hong Kong censorship
           | level, which is much much less restrictive. No VPN or
           | anything needed apart from the SIM card itself.
        
             | hutzlibu wrote:
             | "you'd get the Hong Kong censorship level, which is much
             | much less restrictive."
             | 
             | Didn't that changed since 2018?
        
               | emaro wrote:
               | I'm in China right know with a Mainland/Macao/HK eSIM. My
               | Chinese friend has to use a VPN to access Instagram as
               | did I when I was connected via WiFi in mainland China.
               | Using the eSIM connection I could access Instagram and
               | Youtube without any issues, likewise here in Hongkong
               | (with WiFi).
               | 
               | I didn't investigate how large the difference is, but
               | Hongkong traffic is still treated more liberal.
        
               | monetus wrote:
               | It was really sad seeing all the bookstores close.
        
       | kurtoid wrote:
       | They say UDP is never blocked, so would Wireguard work?
        
       | userbinator wrote:
       | As a result of such blocking, I suspect steganographic techniques
       | are only going to become more popular over time.
        
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