- cypherpunks-legacy@lists.ogf.org

Re: Commercial PGP: Verifying Trustworthiness
by peter honeyman 26 Aug '93

26 Aug '93

> Basically, if both commercial PGP and freeware PGP produce exactly the > same encrypted files as output based on the same keys, and if you have > the source code and can trust freeware PGP, then it can be stated that > commercial PGP is secure. pgp and viacrypt will always generate differnt outputs: pgp adds some pseudo-random stuff to the start of the file it is encrypting to ensure that a file encrypts differently each time. peter

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Commercial PGP: Verifying Trustworthiness
by thug＠phantom.com 26 Aug '93

26 Aug '93

Here's a real simple way to verify the trustworthiness of the commercial version of PGP. It's a bidirectional comparison of outputs. 1) Have freeware PGP generate a set of keys. 2) Using keys from (1) encrypt several files using both conventional and public key encryption using freeware PGP _and_ commercial PGP, then compare the output byte-for-byte of both to see if they match up. 3) Have commercial PGP generate a set of keys. 4) Using keys from (3) encrypt several files using both conventional and public key encryption using freeware PGP _and_ commercial PGP, then compare the output byte-for-byte of both to see if they match up. Basically, if both commercial PGP and freeware PGP produce exactly the same encrypted files as output based on the same keys, and if you have the source code and can trust freeware PGP, then it can be stated that commercial PGP is secure. I'm no expert on mathematical proofs, but the above seems very logical to me. I'm assuming the NSA will pressure ViaCrypt to put in a backdoor. One possible backdoor that can be placed inside the commercial PGP and still allow it to pass the above test is if commericial PGP secretly writes all keys and pass phrases to a block on your hard disk, and marks that block as used to the file system. In order to prevent you from scanning your hard disk and finding that block, the information stored there could be encrypted by a key which the NSA has in it's possession. I would never use commercial PGP because I do not place inherent trust in programs which come with no source code, and commercial PGP doesn't come with source code. Thug

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No Subject
by bryan＠fegmania.wustl.edu 26 Aug '93

26 Aug '93

subscribe bryan@fegmania

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Re: blinding message & newbie questions
by Karl Lui Barrus 26 Aug '93

26 Aug '93

-----BEGIN PGP SIGNED MESSAGE----- [I think I messed up when I responded originally ... KLB] Sure, I'll take questions :-) I may be a little slow in responding at the moment. >> Conceptually, when you blind a message, nobody else can read it. >So "blinding" is a synonym for encryption with your own public >key, aka multiplication by a very-hard-to-factor number? Not exactly. Blinding/Unblinding is multiplication; Encryption/Decryption is exponentiation. While I can unblind a document without knowing phi(n), I cannot decrypt a message without knowing phi(n). Knowing phi(n) is equivalent to knowing how n factors, so this is intractable. phi(n) = Euler totient function. >> under the right circumstances if another >> party digitally signs a blinded message, the unblinded message will >> contain a valid digital signature. >In other words if Alice encrypts and Bob signs, Da(Db(Ea(M))) = Db(M)? >Under what conditions? Does RSA (in PGP) satisfy those conditions? The conditions are usually satisfied. Offhand, the only one I can think of is that x and n must be relatively prime, otherwise there is no inverse of x mod n. With really huge numbers, the chances of guessing x such that gcd(x,n) != 1 are very small. If this does happen, then you've guessed x such that x is a multiple of one of the factors of n! Time for somebody to pick a new p,q, and n :-) As far as PGP, I think the only messages PGP produces are exponentiated. I mean, PGP doesn't produces messages obscured only by a muliplication factor; the ascii snow messages PGP generates are encrypted, signed, compressed, or all of the above. So this doesn't arise. >> If someone asks >> you to digitally sign a random stream of symbols, remember that what you >> sign may be unblinded to reveal a contract, etc. >For what applications would Bob want to sign an encrypted contract >instead of a plaintext? Let me get back on this. I beleive the general name these sorts of protocols go under is "embassy protocols". They are useful in things such a digital cash: blind a message, and get the bank to sign it. Then unblind and you have a valid, digitally signed piece of cash. The bank is unable to track it since it couldn't read it (message was blinded when the bank signed), but the bank can verify that the cash is digitally signed by them. It also arises in automatic protocols: say in computer security. If the computer sends a challenge string which you decrypt and send back, the computer can encrypt with your public key to verify you. If the challenge string is random, you may have unwittingly digitally signed a blinded document that is not in your favor... The cut-and-choose protocol allows a person to sign a blinded document and be sure they aren't signing something else. I'll get back on this as well. /--------------------------------------------------\ | Karl L. Barrus | | klbarrus(a)owlnet.rice.edu | | D1 59 9D 48 72 E9 19 D5 3D F3 93 7E 81 B5 CC 32 | \--------------------------------------------------/ -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLHzwP4OA7OpLWtYzAQEyuQP/Vrc5tB5TfbDc0/FRWN9uALdSZk/JZNwX UYmFfKHQzhYdqJkoOrDE+MMHbJaGuZkuSnYUbIEAFvos6SRPI9doRAvyWnKjQKfp 9h04BMGrB3IoHPBqK59CbH+jNtNc3hYgWw4zSpaFo3+1aEPM+WUHQ2plO2KjJSJg 2M272Y2Y3IE= =tHuX -----END PGP SIGNATURE-----

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Re: Source Code NOT available for ViaCrypt PGP
by James Still 26 Aug '93

26 Aug '93

Carl wrote: >> I think he's trying to run ahead of Clipper and the resulting encryption >ban. >> Make a lot of $$$ from people by selling them soon-to-be-"useless" software. >> What a scam... > >Is anyone taking bets on encryption bans? [...] >If each user of RIPEM or PGP would get one newcomer to start using it >every month, for example, it would take less than 18 months to get the >whole US covered. Are there any volunteers among the Windows guru/programmer's here to kick out a shell that supports PGP? 2.3a is *much* more stable than 2.2 (and runs great from within PGPShell .PIF'd from Windows.) IMHO only a fraction of Carl's newcomers will even take a second look at PGP unless there's an interface for it. Our privacy shtick falls short on the masses that don't understand our zealotry or the need to protect their own privacy. They want it to be *fun* and could care less about the conspiracies involved. First you get the teeming millions to enjoy what they're doing (see? encryption is fun kids!) and more importantly, feel very comfortable using encryption tools. That way if the fateful day of encryption bans does come, these tools will be as hard to take away from them as from a Texan who first learns to shoot his father's gun. ---- still(a)kailua.colorado.edu -------------------------------------

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Re: Source Code NOT available for ViaCrypt PGP
by mbriceno＠aol.com 26 Aug '93

26 Aug '93

Simon Trask writes: > A) No source code will be available, due to the nature of the > agreement between PKP and ViaCrypt. So we are supposed to trust it sight unseen? Why in the world would anyone buy an encryption program of questionable security --which any program for we can not get the source is-- when we can get a supposedy virtually identical program that we know is secure for free? > B) He is under 'a lot' of pressure to have a product 'on the shelves > in under two months', and therefore the first release will be a > MS-DOS version, then Macintosh, SVR4, SUN OS, and all of those unix > versions, and that they will eventualy put out a windows product and > start makeing improvements to the actual product. I can't help but wonder if the guy is feeling other pressures besides time pressures. Just thinking. I don't think that ViaCrypt will make much money of the people on this list. --Marc

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Source Code NOT available for ViaCrypt PGP
by Christian D. Odhner 26 Aug '93

26 Aug '93

I talked once again with Dave Barnheart at ViaCrypt, and he told me: A) No source code will be available, due to the nature of the agreement between PKP and ViaCrypt. B) He is under 'a lot' of pressure to have a product 'on the shelves in under two months', and therefore the first release will be a MS-DOS version, then Macintosh, SVR4, SUN OS, and all of those unix versions, and that they will eventualy put out a windows product and start makeing improvements to the actual product. So in answer to (Paul Goggin's?) questions about verification of changes, "We'll Just Have To Trust Them(tm)" <g> But look on the bright side... This will blow David Sternlight out of the water! Happy Hunting, -Simon Trask <cdodhner(a)indirect.com> PGP public key available upon request.

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Re: Visa, HNC Inc. develo
by Duncan Frissell 26 Aug '93

26 Aug '93

To: cypherpunks(a)toad.com M >Same goes for the supermarket reselling my M >buying patterns. If they can sell information about me, my groceries M >are cheaper (or they make money). Selling personal information is a M >competitive advantage. For most people, this is more important than M >privacy. M > M > Marc But it's trivial in the case of supermarket "Price Plus" card programs to use a nome de guerre and a mail drop (which you should be using in any case). Thus you get the discount and the supermarket gets purchasing info which may or may not match your actual demographics depending on whether or not you lied about those as well as your name on the initial ap. Secured credit cards allow you similar anonymous use of payment facilities (if obtained in a nome de guerre) without surrendering privacy. That said, I realize that it is difficult even to convince civilians of the benfits of receiving all their mail via an agent. They consider it weird. Perhaps "celebrity stalkers" and the general breakdown in civility will ecourage the use of communications screening devices like mail receiving services, voice mail, and the coming network-based communications servers. Duncan Frissell What this metaverse needs is a cheap anonymous communications server for all who want one. This software entity located "somewhere on the nets" would receive all email, voice, fax, video, and VR communications directed to an individual, record and filter them, and forward (anonymously) those communications that meet certain pre-established criteria to its principal located "somewhere on the nets." --- WinQwk 2.0b#0

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info; ATM
by Brian D Williams 26 Aug '93

26 Aug '93

Paul Ferguson wrote; >Forgive me for furthering this slightly off-topic thread, but >Sprint has been offerring Frame Relay data sevices for quite some >time, both for private wide-area networks and for >interconnectivity to the global internet via SprintLink. Now, >Sprint will beat everyone else to the punch offerring up ATM - Too late; MFS plugs in leading-edge network for high-speed data transfers MFS Communications Corp. claimed the technological lead among data communications service providers last week with the launch of its end-to-end asynchronous transfer mode network. MFS, an upstart better known for its successful challenges to local telephone company monopolies, claims to have set up the first ATM network in the country. But analysts say that distinction could be fleeting, as at least one other service provider -- Sprint Corp. -- is expected to offer a similar service by year-end. Although these systems can carry regular telephone conversations, they are most apt to be used to transmit huge volumes of computer data and to make it possible for computers in widely separate locations to work together. Ultimately, Royce Holland, president of MFS, sees ATM networks providing the backbone for a telecommunications infrastructure that supplies movies to home television sets at the touch of a button. Investor's Business Daily -- August 24 -- Page 4 Sprint was also before congress last week asking that MFJ restrictions against the RBOC's entry into long distance be codified into law, and that they (the RBOC's) be restricted from entry into long distance for 10 years! can you say competition? Brian Williams Ameritech data center Cypherpatriot

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Source Code NOT available for ViaCrypt PGP
by vince＠dsi.unimi.it 26 Aug '93

26 Aug '93

> Just thinking. I don't think that ViaCrypt will make much money of > the people on this list. Very true. Too bad that PGP is going commercial. Even worse the fact that sources won't be available. If PGP will become a commercial product and the public domain version will be unsupported or ``left behind'' in respect of the commectial version, then I believe that some hackers will start hacking the public domain version (probably infringing PGP's copyright as well), a new version, newly-featured version of PGP (let's call it NPGP) will start being used and then the commercial version of PGP will become suspect, poorly trusted and unpopular in the Internet community. -- David Vincenzetti, system adminitrator | <vince(a)ghost.dsi.unimi.it> DSI, Universita` degli Studi di Milano, | phone: ++39 2 55006 391 via Comelico 39, 20135 Milan, ITALY | fax: ++39 2 55006 373

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