[HN Gopher] NSA's Backdoor of the PX1000-Cr
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       NSA's Backdoor of the PX1000-Cr
        
       Author : sohkamyung
       Score  : 247 points
       Date   : 2022-02-17 08:09 UTC (14 hours ago)
        
 (HTM) web link (www.cryptomuseum.com)
 (TXT) w3m dump (www.cryptomuseum.com)
        
       | sylware wrote:
       | How this would be different of what exists and is in use today?
       | 
       | Not to mention, the "holes"/"bugs" in the silicium and those in
       | the running software stack. PPL tend to forget about the SDK too:
       | "backdoor injectors for foreign and futur CPUs" aka compilers.
        
         | jacquesm wrote:
         | If it were built today you could expect all of the security
         | features of the best phones on the market and of course far
         | more powerful processors allowing for stronger crypto.
         | 
         | Essentially you'd be looking at a cryptophone.
        
       | tablespoon wrote:
       | > In this context it would be interesting to know whether the NSA
       | had deliberately weakened the PX-1000's cipher, in order to
       | monitor the ANC communications.
       | 
       | Honestly, that seems a little far fetched. This kind of thing
       | seems like something that would be smart to do with no particular
       | target in mind, with the idea that it could be opportunistically
       | exploited later.
       | 
       | Anyone who goes out an buys a specialized encryption device,
       | especially in the 80s, probably has a high likelihood of being up
       | to things the authorities have an interest in.
        
       | richardfey wrote:
       | Somewhere at NSA there must be an equivalent museum with the
       | hardware that helps deciphering PX1000-Cr ciphertexts
        
         | Rebelgecko wrote:
         | If you're ever in the area, NSA's public museum is 100% worth a
         | visit. Not surprisingly they skip over things that make them
         | look bad, but it's really cool to be able to play with real
         | enigma machines. They do have an exhibit on secure
         | telecommunications hardware, although I don't remember if this
         | device is included (IIRC it's mostly landlines and more modern
         | cell phones)
        
       | jacquesm wrote:
       | I knew the director of Textlite, Hugo Krop. He was active as an
       | investor as well, a coke junk and went around with a body guard
       | with a gun at all times driving a black armored (so he claimed)
       | Mercedes.
       | 
       | Textlite was the brand used for the LED light bars which they
       | designed and manufactured, and which were a runaway success.
       | 
       | The PX-1000 was his brainchild too, but it never got the market
       | adoption that they were hoping for.
       | 
       | More information [1], [2].
       | 
       | Weird but interesting character. Hugo had a bit of a lifestyle
       | problem (to put it mildly) and when Textlite cratered he went
       | into all kinds of really shady deals, one of which was a fund
       | that ostensibly grew trees in Latin America.
       | 
       | Eventually he went to jail [3] because it turned out that those
       | forests of trees didn't exist. He died recently (in 2018).
       | 
       | I have a lot of funny and some not so funny stories about Hugo,
       | he wasn't the nicest man due to his habit but when sober and
       | clean was smart and interesting to talk to and tuned in to trends
       | that others only saw much later. You can think of the PX-1000 as
       | an early version of what today would be called a cryptophone, a
       | mobile way for people to communicate securely.
       | 
       | What is interesting is that in this particular context instead of
       | the main use case highlighted being criminals the case of Nelson
       | Mandela and his army of supporters is used to exemplify the power
       | of such a device.
       | 
       | This was in the age when all information traveled in plaintext
       | and to suddenly have someone sell a device that afforded 'pretty
       | good privacy' was a thing that the intelligence services found
       | hard to deal with.
       | 
       | [1] https://www.groene.nl/artikel/versleuteld-maar-niet-voor-
       | ame...
       | 
       | [2]
       | https://www.vpro.nl/argos/lees/onderwerpen/cryptoleaks/2020/...
       | 
       | [3] https://www.blikopdewereld.nl/economie/beleggersinfo/de-
       | bele...
        
         | silasdavis wrote:
         | How did you become acquainted?
        
           | jacquesm wrote:
           | That's a very long story, the in-a-nutshell version: walking
           | at night in Amsterdam I spotted two guys hauling an Apple II,
           | disk drives, a monitor and a bunch of expansion cards out of
           | the back of a car, I asked what they were doing and they said
           | that they were making some kind of computer vision device
           | (this was in 1984, I was 19 at the time, what they were
           | building was an eye tracker), I asked if I could tag along
           | and they said ok, after an hour or so it was clear they had
           | no clue what they were doing (trying to write some basic
           | program to talk to their frame grabber) so I coded the whole
           | thing up without an assembler by poking the machine code into
           | some free RAM. This led to a longer term relationship, the
           | one guy was an optics genius called Michiel Kassies, the
           | other a guy that knew a lot about hardware, Karl Jungbauer
           | who worked for NikHef (the dutch institute for Nuclear
           | Physics) in their hardware department and who moonlighted in
           | the tech scene in Amsterdam in his free time. Michiel knew
           | Hugo, and when Hugo got the proposal to invest in Jan Sloots'
           | fake video compressor he asked me to look it over for him,
           | which I did.
           | 
           | Hugo ended up investing in DadaData, a company founded by
           | Jungbauer, a guy called Peter Domela-Nieuwenhuis and myself,
           | after three weeks I realized these guys were more interested
           | in their drugs than in running a business so I bailed out and
           | founded MCS, which still continues today (though it has been
           | renamed).
           | 
           | Over the years Hugo would come up with all kinds of weird
           | ideas and occasionally he'd call. We lost touch prior to
           | Greenmix, by which time his drug use became so bad that there
           | we no more normal times.
           | 
           | It's pretty weird to see someone you respect initially slide
           | off like that, I have always hated drugs and it made it
           | pretty hard for me to be exposed to it without commenting on
           | it and getting into arguments. Hugo _really_ was a nice guy
           | that lost it, his addiction to his dope and lifestyle eroded
           | every sense of what was right and what wasn 't. The path of
           | destruction he left behind is a mile wide and even though he
           | spent 12 months in jail I'm pretty sure there are lots of
           | people around here that would happily piss on his grave.
           | 
           | Of course I'm sorry for all the investors that lost their
           | money in his harebrained schemes, but I mostly pity his kid
           | who saw his father slide down like that.
           | 
           | One of the funnier stories about Hugo: he was very much
           | overweight and the doctor told him to get some exercise or
           | that he'd die of a heart attack in short order. So he went
           | bike shopping and picked out a very fancy racing bike. After
           | 6 months of dutifully disappearing each day for two hours on
           | his bike he complained that he didn't lose any weight. So I
           | offered to ride with him to see what was going on. Hugo lived
           | in Loosdrecht at the time, and from his house made a beeline
           | to a pancake restaurant in Vreeland (a couple of km away from
           | his house), where he ate two _enormous_ pancakes, consumed
           | copious amounts of expensive alcohol and then cycled
           | leisurely back. So at least I understood why the weight loss
           | program was a failure :), but he swore me to secrecy (which I
           | am now breaking, but I don 't think he'd mind).
        
             | mstef wrote:
             | fascinating details, happy to have stirred up these
             | memories!
        
               | jacquesm wrote:
               | I've been reading for a couple of hours on all of the
               | stuff you guys have dug up on the pocket telex (and other
               | interesting bits and pieces), very impressive. So much
               | detail, this must have been a lot of work, and other than
               | a couple of typos I can't find anything that doesn't
               | match what I already knew about the device. It would be
               | interesting to know who formed the software team from
               | those days, I wished I recalled more names.
               | 
               | Above the offices in Amsterdam Zuidoost (Hogehilweg) they
               | had this insanely extravagant bar. Looking back I think
               | that the armed bodyguard must have been either coke-
               | induced paranoia shining through or a sign that there was
               | already more afoot that could not stand the light of day.
        
               | jacquesm wrote:
               | By the way, doesn't this page need an update now?
               | 
               | https://cryptomuseum.com/crypto/philips/index.htm
               | 
               | "The Philips version with encryption (PX-1000Cr)
               | contained a much improved cryptographic algorithm."
        
               | cryptopaul wrote:
               | Hi, Paul from Crypto Museum here. Thanks for bringing
               | this to my attention. I missed that one when updating the
               | stories.
        
             | Daniel_sk wrote:
             | Wow, very interesting - thanks for sharing. There are so
             | many moments like these and they get lost in history...
        
               | jacquesm wrote:
               | What really bothers me - even after all those years - is
               | that if not for the drugs these guys would have gone so
               | much further than they did. They had every opportunity,
               | the tools, the brains, the timing and they fucked it all
               | up.
        
               | bitwize wrote:
               | Kind of reminds me of Phil Katz. Brilliant guy, but a
               | raging drunk. When he died, Wired or somebody interviewed
               | the strippers at the strip club he used to go to, who
               | said that he was very lonely and looking for someone to
               | talk to.
        
               | bredren wrote:
               | Possibly. For some, substance abuse is one escape--one
               | way of dealing with inner demons. There are other
               | destructive, occupying things than substances that can
               | stop talent and productive potential from yielding much
               | at all
        
             | tmnstr85 wrote:
             | This story made my day. Thank you!
        
       | gzer0 wrote:
       | There is good reason to believe the weaknesses introduced by the
       | NSA with the PX1000-cr algorithm were introduced as part of a
       | series of multiple backdoors that cooperate together [2][3].
       | 
       | The equation system to be solved is rather huge (~20 megabytes
       | when shown as ASCII text), therefore it is logical to assume the
       | NSA required more efficient techniques to break it in the 1980s.
       | 
       | The fact that the first and last character, as well as the top
       | bits in between, leak the keystream makes for an easy and cheap
       | attack that amortizes the algebraic attack costs. Detection of
       | key re-use is therefore trivial.
       | 
       | And since this is a stream cipher key reuse, it is
       | cryptographically disastrous; an excellent illustration of this
       | is the Venona project [1].The NSA has spent decades trying to
       | recover plaintext from two-timepads, but in the Venona case they
       | did not know which two messages shared the same key. This is
       | significantly simpler with the PX1000-cr.
       | 
       | For Venona, it is a safe guess that the NSA developed a
       | significant amount of HW capable of recovering plaintext from two
       | plaintexts that have been XOR-ed together. This implies they may
       | employ more costly algebraic or other attacks only on cryptograms
       | with unique keys. This, I feel, is a critical insight: there is
       | not a single backdoor here, but numerous ones that cooperate.
       | 
       | [1] https://en.wikipedia.org/wiki/Venona_project
       | 
       | [2] https://www.alchemistowl.org/pocorgtfo/pocorgtfo21.pdf
       | 
       | [3]
       | https://www.ctrlc.hu/~stef/blog/posts/pocorgtfo_21_12_apocry...
        
         | djmips wrote:
         | Fascinating person. This device really does feel ahead of it's
         | time. What was his story for the period after the tree scam
         | till his death?
        
           | jacquesm wrote:
           | I suspect you are in the wrong part of the thread so I'll
           | answer you here.
           | 
           | I do not know, I lost contact with him and only read about
           | him in the paper after that period.
           | 
           | He had some _really_ unsavory characters hanging around him
           | and that plus the drugs were the main reason for me to stop
           | interaction with him. There are some rumors that the funds
           | raised with Greenmix were used to finance drug transports, I
           | have no clue if these are true or not but if they were it
           | wouldn 't surprise me even a little bit.
        
         | mstef wrote:
         | nice summary of my post! thank you very much
        
         | mhh__ wrote:
         | Venona dumps are apparently still embarrassing enough that
         | they're only being drip published still even today. I don't
         | think the original Russian is declassified at all.
        
         | akira2501 wrote:
         | > The equation system to be solved is rather huge (~20
         | megabytes when shown as ASCII text), therefore it is logical to
         | assume the NSA required more efficient techniques to break it
         | in the 1980s.
         | 
         | I would assume they're far more capable of building custom
         | hardware to accomplish these attacks than needing to do all of
         | them in software, especially in the 1980s.
        
       | nonrandomstring wrote:
       | The algorithm itself looks pretty strong for time but weaker than
       | DES having a 16 byte non-linear function in a cipher feedback
       | loop without chaining. Due to the way the registers aren't
       | randomised and the key is entered it leaks plain-text quite
       | badly. The story here is that Stefan Marsiske studied the
       | algorithm and wrote a cracker that can break a PX-1000Cr message
       | in 4 seconds on a modern laptop, with just 17 characters of
       | cipher-text. Some of the story speculates on the effect this
       | backdoor may have had on anti-apartheid in the 80s and an
       | anecdotal conclusion that a developer had tipped-off the movement
       | about weakened cryptography and helped them revert to a secure
       | version of the PX-1000.
        
       | Cryptanalyse wrote:
        
       | marrold wrote:
       | A few of us have bought rebadged versions of these recently and
       | we're looking to create a backend for them that accepts a call
       | (probably via SIP / VoIP) and then demodulates the v.23 and does
       | something useful with it.
       | 
       | Are you aware of anyone thats done this already?
       | 
       | Thanks
        
       | throwaway4good wrote:
       | Good thing that they don't do this sort of thing anymore.
        
       | nimbius wrote:
       | for those willing to discount the revelation as cold-war era
       | chicanery, a more recent example exists in the SPECK cipher
       | fiasco where the community, frustrated by statist stonewalling
       | and theatrical bloviation, basically told the NSA to pound sand
       | down a rat hole and refused to incorporate the cipher into the
       | kernel.
       | 
       | https://en.wikipedia.org/wiki/Speck_%28cipher%29
        
         | jacquesm wrote:
         | Yes, the NSA is fantastic at cryptography but doesn't
         | understand the concept of broken trust.
        
       | axiosgunnar wrote:
       | > Although he hasn't found the smoking gun (yet)
       | 
       | So the author is admitting to the title being fake news?
        
         | mstef wrote:
         | actually since large parts of my addendum blog post were quoted
         | here, here is another quote:
         | 
         | > lets me conclude that the PX1000cr algorithm is indeed a
         | confirmed backdoor.
         | 
         | I guess, me and the cryptomuseum people had a misunderstanding
         | about this.
        
           | mstef wrote:
           | i mean an algebraic full key recovery out of 17 ciphertext
           | chars is nothing else but catastrophic. and i'm sure this can
           | be done much more efficiently.
        
           | axiosgunnar wrote:
           | Oh hi! And thanks for the clearup!
        
       | drzaiusapelord wrote:
       | This is also a great commentary on the inherit untrustworthiness
       | of for-profit corporations. From a capitalist perspective trading
       | the security of your users for some early commercial advantage
       | like those 1977 algos from the NSA is "worth it," and the cost is
       | unseen (allowing backdoors) and never disclosed to the customer
       | (dishonesty). There's no one watching this, no rules, and people
       | like Nelson Mandela were victimized because of this. Whenever I
       | meet someone who refuses to run secure systems on anything but
       | FOSS, I respect that they accept that capitalism is a failure in
       | this regard, and a huge one at that.
       | 
       | I have no idea what commercial products are secure now, and
       | neither do you. That's a problem.
        
       | mstef wrote:
       | author of the break here, ama.
        
         | marrold wrote:
         | A few of us have bought rebadged versions of these recently and
         | we're looking to create a backend for them that accepts a call
         | (probably via SIP / VoIP) and then demodulates the v.23 and
         | does something useful with it.
         | 
         | Are you aware of anyone thats done this already? We're not
         | desperate to support the encryption initially but I guess it
         | would be nice too.
         | 
         | Thanks
        
           | flyinghamster wrote:
           | The SpanDSP library has low-speed FSK modem implementations
           | (including Bell 202 and V.23). I've employed the 202
           | demodulator to listen in to some radio-based telemetry.
           | 
           | https://github.com/freeswitch/spandsp
        
           | mstef wrote:
           | sorry, no. but there is an emulator[1], so you can test the
           | roms, or you can write your own code and test it without
           | having the hw.
           | 
           | [1] https://github.com/iddq/sim68xx/tree/px1000
        
             | marrold wrote:
             | Nice, thanks
        
         | sounds wrote:
         | I'm curious whether there is any info on the dev team who
         | created the PX-1000 (where PC-1000Cr is implemented). Any more
         | info on how the NSA got a backdoor inserted? There's [1] which
         | gives a general overview.
         | 
         | This seems like a fascinating story, would be happy to read
         | more!
         | 
         | [1] https://www.cryptomuseum.com/crypto/philips/px1000/nsa.htm
        
           | mstef wrote:
           | afaik the firmware was developed by philips ufsa[1] based on
           | directions (test vectors?) by the NSA, lots of effort was put
           | into making the algo run efficiently on the CPU in the
           | px1000.
           | 
           | [1] https://www.cryptomuseum.com/crypto/philips/usfa.htm
        
           | mstef wrote:
           | also interesting might be this generic link unrelated to the
           | NSA backdoor: https://cryptomuseum.com/crypto/philips/px1000/
        
         | classichasclass wrote:
         | I've got a pair of these somewhere, acquired domestically (USA)
         | AFAIR. Assuming these are crypto-enabled, any easy way to tell
         | what firmware is in them?
         | 
         | Edit: These are Text-Tells.
        
           | mstef wrote:
           | see the section "Different Versions" on this page:
           | https://cryptomuseum.com/crypto/philips/px1000/
        
         | [deleted]
        
         | jacquesm wrote:
         | Cool job, that brought back a lot of memories.
        
         | mperham wrote:
         | What the heck is PX1000Cr???
         | 
         | I've been in tech for decades and have never heard of this. The
         | link offers no actual explanation. Could you supply some
         | background?
         | 
         | Edit: found this
         | https://www.cryptomuseum.com/crypto/philips/px1000/nsa.htm
        
       | 1024core wrote:
       | For those of us not really plugged into the crypto world: what is
       | PX-1000Cr? Why is it important? Where is it used?
        
         | mstef wrote:
         | it's a pocket telex from the early 80ies, you can read more
         | about the device here:
         | https://www.cryptomuseum.com/crypto/philips/px1000/index.htm
        
       | dmix wrote:
       | I love the design of these products
       | https://cryptomuseum.com/crypto/philips/index.htm
        
         | jacquesm wrote:
         | Once upon a time Philips was a world renowned brand in
         | electronics, extremely innovative and their gear was top notch.
         | How it all went to hell I still don't fully understand, but in
         | the late 80's or so their quality started going downhill and
         | they seemed to make one bad move after another.
         | 
         | This stuff is from various eras but not all of the designs are
         | theirs (though all the gear prior to and including the 'spendex
         | 50' was in house design work.
        
       | hyper_reality wrote:
       | This is fascinating and a great bit of work by Stefan Marsiske.
       | Loved the technical writeup in PoC||GTFO too. This quote from the
       | TFA really shows just how difficult it was for the public to
       | access decent cryptography at the time:
       | 
       | > In her book Operatie Vula, Conny Braam explains how one of her
       | people met a guy, by the name of Floris, in a pub in Amsterdam,
       | who allegedly had developed the PX-1000 [5]. From him they
       | learned that the device had been taken off the market as its
       | encryption was too strong. It had been replaced by a calculator
       | but he suggested to find the older version with built-in crypto.
       | 
       | In all I would say it was a pretty good backdoor for the early
       | 80s, showing how far ahead the NSA's internal understanding of
       | cryptography was. I wonder if they would have anticipated the
       | world we live in today where state-of-the-art cryptography is
       | available and used by everyone on the Internet.
        
         | mstef wrote:
         | thank you! may i return the compliments? i love playing on
         | cryptohack.org so many fun and educational challenges! kudos!
        
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       (page generated 2022-02-17 23:01 UTC)