[HN Gopher] PGPP (Pretty Good Phone Privacy) Beta Launch
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       PGPP (Pretty Good Phone Privacy) Beta Launch
        
       Author : todsacerdoti
       Score  : 63 points
       Date   : 2022-08-11 17:53 UTC (5 hours ago)
        
 (HTM) web link (invisv.com)
 (TXT) w3m dump (invisv.com)
        
       | NoImmatureAdHom wrote:
       | I would love to buy your product, but won't yet. I need a few
       | things:
       | 
       | 1) You should explicitly test with privacy-respecting Android
       | flavors like GrapheneOS. I assume it would work using the
       | sandboxed play services hack, but I'm not sure.
       | 
       | 2) You need another exit aside from London. U.K. has weak data
       | protections, facilitates U.S. spying, doesn't even offer access
       | to the real internet any more (they run a firewall and mandate
       | various other kinds of nannying), and, generally, seems like it's
       | sliding down the path towards some sort of oppressive
       | surveillance state.
       | 
       | 3) I need to be able to pay with cryptocurrency, ideally Monero.
        
         | barathr wrote:
         | Thanks -- to your comments / questions:
         | 
         | 1) we have tested with GrapheneOS and it does work. Relay works
         | well with GrapheneOS. With some amount of configuration, the
         | mobile plans also work, though it can be a bit tricky to set
         | up.
         | 
         | 2) We have many egresses (via Fastly) -- across North America,
         | South America, Europe, and Asia -- and more planned. The London
         | egress is used when you're on mobile data by default, but if
         | you're on WiFi then you can egress elsewhere.
         | 
         | 3) Not sure about that at the moment, but we've gotten the
         | request from multiple folks.
        
       | pledess wrote:
       | It looks like the U.S. trademark for "PRETTY GOOD PRIVACY"
       | (Registration Number 2015027) has "Cancellation Date April 24,
       | 2020" even though the one for "PGP" (Registration Number 1914615
       | - with the identical "computer programs for data communications
       | applications, and for the encryption and authentication of
       | electronic information" description) isn't canceled.
       | 
       | Was this relevant to making the "likelihood of confusion" low
       | enough that there's no risk of needing to rename the Pretty Good
       | Phone Privacy product?
        
       | deathgripsss wrote:
       | Has the source code been audited?
        
       | buzzy_hacker wrote:
       | So without this, your internet activity on a mobile phone can be
       | linked to you even with a VPN?
        
         | prschmitt wrote:
         | Yes. With a traditional VPN you are trusting that VPN provider
         | with all of your traffic. They know your identity and
         | everything you do. The two hop architecture we use decouples
         | that information such that neither hop has both the user's
         | identity and their usage information. In our case, the second
         | hop is Fastly.
        
           | buzzy_hacker wrote:
           | Yes, that's true. But let's say I trust my VPN provider and
           | do not trust my cell service provider. Does PGPP add value
           | for me in that case?
        
       | throwaway67743 wrote:
       | I commented on a previous post and while it's sort of been
       | answered here i think it still merits being included:
       | https://news.ycombinator.com/item?id=32397969
       | 
       | I still do find it disingenuous to omit it entirely as it implies
       | that all possible issues are averted which they absolutely are
       | not, even if IMEI wasn't a factor.
        
       | barathr wrote:
       | Just wanted to say hi - I'm one of the co-founders of this effort
       | and would love to answer any questions or discuss further.
       | 
       | Also wanted to add, since this is a common question: does PGPP
       | protect all identifiers or just some? As with most privacy
       | systems, just some. Our aim is twofold: 1) to decouple a user's
       | human identity from their network identities (mobile and
       | Internet) and 2) randomize their network identities. We view
       | decoupling as pretty fundamental to practical privacy -- to
       | decouple who you are from what you do. Who you are in the context
       | of the network is your human identity, often associated with the
       | main point of contact you have with the network and billing --
       | your subscription and SIM, your broadband connection and its IP
       | address and your home address, etc. That information has been
       | used as the key upon which datasets can be attached. The goal
       | then is to decouple across entities -- the different parties who
       | have data -- and across uses -- the different mechanisms of a
       | network protocol, such as authentication and connectivity.
       | 
       | Other identifiers such as hardware identifiers aren't inherently
       | attached to a person and aren't always used by networks, but even
       | when they are, removing them is insufficient -- as our colleagues
       | at UCSD found in recent work, phones can be identified at the
       | PHY, without even using a unique hardware identifier.
        
         | sneak wrote:
         | Does this also randomize the IMEI, or just the IMSI?
         | 
         | Seems like if the same IMEI shows up over and over again with a
         | different rotating IMSI then the jig is up.
        
           | barathr wrote:
           | The IMSI. We don't do anything with the IMEI ourselves (it's
           | in the category of hardware identifiers that I'm mentioning
           | above). Some phones can change them when rooted, some can't.
           | The network attach process doesn't use the IMEI inherently by
           | spec, but some cell cores can query for it (for example, to
           | block stolen phones). It's not a network identifier, and
           | strange things sometimes happen with the IMEI that don't even
           | affect connectivity --
           | https://www.androidauthority.com/duplicate-imei-vivo-
           | india-1...
        
             | throwaway67743 wrote:
             | I think you should clarify this, changing the IMEI in most
             | countries is a criminal offence, do not keep brushing this
             | topic off.
        
             | sneak wrote:
             | > _The network attach process doesn 't use the IMEI
             | inherently by spec, but some cell cores can query for it
             | (for example, to block stolen phones)._
             | 
             | How widespread is this practice? Do the major US carriers
             | know my IMEI?
             | 
             | I tend to believe that they do from what I've seen in their
             | web interfaces, and that IMSI rotation alone is basically
             | pointless from a privacy standpoint.
        
               | barathr wrote:
               | This is one of the problems with mobile -- there's isn't
               | any one universally correct answer to this (or most
               | questions), so I'll answer to the best of my knowledge.
               | IMSIs are what are associated with your identity (because
               | it's your SIM and service) in a normal mobile plan, and
               | it's what was (is?) used by carriers when they aggregate
               | / analyze / sell location data.
               | 
               | IMEIs can be queried by a network core (not the tower)
               | and US carriers probably do this every once in a while to
               | check against their stolen phone database. It can be
               | changed on some devices but not others. It's not
               | inherently tied to you as a person but of course it is
               | tied to that device.
               | 
               | For those who don't need mobile data service of any sort,
               | I think that PGPP Relay does what's needed -- decouples
               | your IP from your identity -- and you can use WiFi
               | networks without revealing anything.
        
               | sneak wrote:
               | > _IMEIs can be queried by a network core (not the tower)
               | and US carriers probably do this every once in a while to
               | check against their stolen phone database. It can be
               | changed on some devices but not others. It 's not
               | inherently tied to you as a person but of course it is
               | tied to that device._
               | 
               | It's also linked to the rotating IMSI, so all of the
               | rotating IMSIs that are used at the times the IMEI is
               | interrogated are linked together from a metadata
               | standpoint.
               | 
               | They're also all linked to every other IMSI that was ever
               | used with that IMEI (at the times the IMEI is
               | interrogated).
               | 
               | > _US carriers probably do this every once in a while to
               | check against their stolen phone database_
               | 
               | Hourly? Daily? Monthly? Only on first-time seeing a new
               | IMSI?
        
               | biktor_gj wrote:
               | Probably on every connect, there are ways to randomize
               | your IMEI on every boot on certain phones though (that
               | might be not very legal in some countries)
        
               | throwaway67743 wrote:
               | Please familiarise yourself with how cell networks
               | actually work, you can't throw out comments like this
               | because it's just not true.
        
         | throwaway81523 wrote:
         | Um what? Is PRZ involved? Is he ok with your using that name?
         | He had something called PGPFone a long time ago, though it
         | didn't get much traction. There have also been tons of other
         | encrypted voice programs.
         | 
         | Obscuring traffic patterns without stupendous amounts of dummy
         | traffic is quite difficult. That someone is connected to your
         | network at all is already a huge giveaway. I have trouble
         | seeing how something like this can work without a very big
         | operator (think Cloudflare or AWS) being involved, and anything
         | that size would have to get in bed with regulators. It's a lot
         | easier if you're only trying to do low bandwidth text.
        
           | mrex wrote:
           | >He had something called PGPFone a long time ago, though it
           | didn't get much traction.
           | 
           | Does anyone have a copy of it? I can't find it ANYWHERE.
           | Actually used it way back when, it worked surprisingly OK and
           | was the first softphone I used.
        
         | nibbleshifter wrote:
         | What payment methods are available, and what data do you
         | collect for billing?
         | 
         | Could I pick up an eSIM compatible Android tomorrow for cash at
         | the local pawn shop, and get service using your system without
         | handing over anything identifiable?
        
           | barathr wrote:
           | Right now we use Stripe (mostly because it's the the most
           | rock solid choice for payments) -- we don't ask for name or
           | email, though of course Stripe could know that as a card
           | processor. But our approach goes back to decoupling human
           | identity from network identity -- what that payment says is
           | that the holder of that card is a subscriber of the service
           | but not, for example, what network ID you got.
        
             | nibbleshifter wrote:
             | Once you accept some kind of privacy coin (monero) I'll be
             | delighted to buy a years service upfront.
             | 
             | I imagine many others will be in the same position.
             | 
             | Obviously taking crypto will mean upfront prepayment of
             | accounts (like prepaid mobile credit) instead of monthly
             | billing and will require some reworking.
        
             | unknownaccount wrote:
             | Why not accept cryptocurrency?
        
             | sneak wrote:
             | Your somewhat evasive answers don't really instill
             | confidence.
             | 
             | The answer is no, you cannot. Payment cards are PII.
        
               | barathr wrote:
               | I don't see what was evasive, happy to answer in more
               | detail if there's something you're seeing not answered
               | above. We use Stripe as a credit card processor -- so we
               | have what Stripe's (very well documented) APIs provide.
               | That reveals that you purchased the service, but we don't
               | know anything about the _network_ identity you have nor
               | your Internet usage, because architecturally we don 't
               | have that information.
               | 
               | I understand that revealing that information to Stripe
               | may not be acceptable -- not sure what to say to that.
               | We've gotten requests for other forms of payments and we
               | can consider it, but we don't support anything other than
               | credit cards at the moment. (There are credit cards that
               | aren't linked to a person, if that's a better option.)
        
               | nibbleshifter wrote:
               | > There are credit cards that aren't linked to a person
               | 
               | My desire to know more intensifies.
        
               | selectodude wrote:
               | https://www.amexgiftcard.com/
               | 
               | Go to the grocery store, buy with cash, you're good to
               | go.
        
               | sneak wrote:
               | No. All payment cards in the United States require strong
               | government identity and KYC, per US federal law. To
               | activate these cards you must provide identity
               | information. Providing false information is a crime.
        
               | jjulius wrote:
               | >No.
               | 
               | No. Gift cards can be purchased in-person in the US, with
               | cash. Said gift cards are activated at the register upon
               | purchase. These can then be gifted to someone else, and
               | further activation (or registering your personal
               | information with the card) is not required.
               | 
               | Edit: I just checked the Visa gift card issuer's site for
               | a card I have (and never had to activate or provide
               | personal information to), and for shopping online it just
               | says:
               | 
               | >In the Payment Method section, enter the Card
               | information as you would a credit or debit card. In the
               | Billing Address section, fill in your name and address.
               | 
               | So when I check out online, I can enter any information
               | that I like, presumably as long as it ties back to a
               | valid address of some kind - there is zero effort on the
               | part of the card issuer to verify that I am who I say I
               | am. I would _only_ need a PIN when making purchases with
               | it as a debit card in-person. I should make it clear that
               | I 'm not saying that providing false information is
               | legal, just that the point about being required to
               | provide "strong government identity" to activate gift
               | cards has been false for a long time.
        
               | cmroanirgo wrote:
               | You can buy visa gift cards for cash
        
               | nibbleshifter wrote:
               | I haven't been able to do that in Europe without
               | providing ID for well over a decade.
        
             | NoImmatureAdHom wrote:
             | Thanks for working on this, I can't wait to give you my
             | money.
             | 
             | It seems like you're misreading a key market segment if you
             | don't offer cryptocurrency payments (particularly Monero).
        
         | codethief wrote:
         | Hi barathr, thanks for joining the discussion! Having had a
         | brief look at your paper and the Usenix slides[0], I've got
         | three questions:
         | 
         | - Given that your Android app is security-critical for its
         | users, are you planning on open-sourcing it in the near future?
         | 
         | - How exactly does your app work on Android? How does it rotate
         | the IMSI? (I don't know a lot about eSIMs but I would have
         | thought a regular app can't easily change the carrier/network
         | settings.)
         | 
         | - As for the relay functionality, I suppose on Android this
         | "simply" sets up a VPN once the network connection is
         | established?
         | 
         | [0]:
         | https://www.usenix.org/conference/usenixsecurity21/presentat...
        
       | throwaway743 wrote:
       | Definitely want to try this, but the full feature cost is much
       | more than my monthly phone bill. Does this route through a server
       | at all (overhead costs) or is everything contained locally?
       | Trying to understand the level of rationale for such a cost.
       | 
       | If it's contained locally, it's likely you could make more in
       | volume than with a higher price.
       | 
       | Also, it's deceptive/leaves a bad taste in mouth with having the
       | Play Store show an "Install" button rather than purchase, only to
       | open the app to a paywall. Using this dark pattern could end up
       | hurting user perception/the app's reviews.
        
         | barathr wrote:
         | Hmm, thanks for that feedback. I think (hope?) people wouldn't
         | think that service like this was free (the prices reflect the
         | costs). We say pretty clearly on our site what the prices are
         | and are trying to be upfront. It's true that the payment isn't
         | handled by Google but by Stripe, so you aren't buying it on the
         | Play Store, but that's because it's a network service,
         | something that isn't under Google's normal payment processing.
        
         | max-b wrote:
         | The $5/month price is for the Relay functionality which
         | provides the 2-hop traffic tunneling. I'm guessing(?) that's
         | not more than your monthly phone bill?
         | 
         | The $90/month price is for unlimited mobile data, so it would
         | in theory replace your phone bill entirely.
        
       | wjko21 wrote:
       | Can you give a run-down what's involved in getting service? Would
       | I need to register with you and get an app or something? Which
       | devices are supported? Do I need rooted device?
        
         | barathr wrote:
         | You can just install the app on a normal device and subscribe
         | to the service on first run. For PGPP Relay, almost any Android
         | device (and maybe even Chromebooks) works fine. For PGPP Mobile
         | plans, you'd need an eSIM capable device (e.g. Pixel 4 or newer
         | or Samsung S22).
        
       | JediPig wrote:
       | anything funded by gov is going to have a backdoor... this is
       | funded by Princeton / Gov...
       | 
       | So no, make a different solution.
        
         | prschmitt wrote:
         | This was a research project that we undertook while at our
         | respective universities. We decided to spin it out as we think
         | it's useful. We are not funded by the government or Princeton
         | (while Princeton owns the IP).
        
       | syrrim wrote:
       | >PGPP does not support traditional phone calling/SMS and doesn't
       | include a phone number. Instead we recommend that users install
       | and use more secure apps such as Signal and Matrix for voice and
       | video.
       | 
       | Doesn't signal require a phone number to use? Or did they fix
       | that?
        
         | barathr wrote:
         | It does, but you can use any number, even a VoIP number. (And
         | you can connect to the VoIP provider with PGPP Relay enabled.)
        
           | baobob wrote:
           | Just a little feedback (worth a dime or a damn, you decide),
           | but I come here for the comments first to judge whether
           | clicking the link is worthwhile. The problem discussed in the
           | parent comments would completely rule me out as a user:
           | solving privacy is not a technical problem, it has always
           | been a usability problem. This is primarily why your namesake
           | failed - variations on wizardry that ultimately result in a
           | user still having to jump through hoops to accomplish simple
           | tasks sounds like the same thing all over again to me
        
             | barathr wrote:
             | I tend to not take this as a black and white matter -- I
             | see privacy as a layered problem -- at multiple
             | network/software layers -- and as a policy and user
             | behavior question. No single response, whether user
             | education, policy, technology, etc. can perfectly solve
             | something as complex and nebulous as privacy. (It gets
             | worse when we think about the contextual nature of privacy
             | -- that what we want out of it depends on the parties
             | involved, even the time of day.)
        
       | chmod775 wrote:
       | I don't like that this is piggybacking on the recognizable name
       | of an open standard and not-for-profit software while being
       | considerably less open (Where's the RFC? Where's the source
       | code?) and being for-profit.
       | 
       | This is a bit like calling your company "Red Cross
       | Pharmaceuticals" despite not being affiliated with them.
        
       | jimhi wrote:
       | You assign users a temporary IMSI which is done in the cloud
       | right?
       | 
       | How does this protect against IMSI catchers and Stingrays if they
       | are done local to you? Local cell tower spoofing?
       | 
       | Also, this is just for data? So if you have another SIM for
       | voice/SMS this is completely negated?
        
         | prschmitt wrote:
         | By decoupling the user identity from a permanent, globally
         | unique IMSI, we make IMSI catcher / Stingray attacks less
         | "useful" as the IMSI is changing and isn't tied to the user.
         | They can attack your IMSI, but it won't be tied to you and it
         | is ephemeral.
        
       | fire wrote:
       | what does "high-speed" mobile data mean in terms of actual
       | throughput?
        
         | prschmitt wrote:
         | As with all mobile service it really depends on coverage in
         | your area. The baseline service is LTE.
        
       | trinsic2 wrote:
       | So what happens when the major mobile networks decide to stop
       | allowing PGPP to use their network?
       | 
       | I seen this happen before. I used to use the "Private Buyer"
       | Payment service to anonymously pay for services privately. They
       | had issues with payment processors preventing their payments from
       | going through. I gather largely due to the privacy aspects of the
       | service. That was in the early 2000 and I think the went out of
       | business after 3-5 years.
        
         | barathr wrote:
         | It's true, they could. The one thing that is perhaps helping at
         | this moment is that they've come under scrutiny for their (bad)
         | privacy practices -- both from the media and from the FCC.
         | Ultimately we see privacy as a layered problem, from a
         | technological standpoint and a social standpoint -- we need
         | layers of protection across the network and software stack and
         | also a combination of policy, technology, and user behavioral
         | changes.
        
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       (page generated 2022-08-11 23:01 UTC)