December 2003 - cypherpunks-legacy

Re: (Fwd) What motivates Cryp
by jamiel＠sybase.com 17 Dec '03

17 Dec '03

At 7:55 AM 07/01/94 -0400, Duncan Frissell wrote: >J >Similarly my motivations for >J >using cryptography come simply from a desire for privacy from >J >Govt. and other snooping but NOT from the 'cyber-survivalist' >J >inclinations that seem to motivate some in the US at least. > >Distinguish "desire for privacy from Govt." and "'cyber-survivalist' >inclinations" -- seems like the identical motive. It *is* government that >digital volunteerists (a friendlier term) seek privacy from. The same as "desire for safety from thugs" and "NRA-Nut". I don't subscribe to the theory that I need to have a gun to keep myself safe, and I am antigun, but such as the US is now, I can see myself buying one under some ocnditions and being first in line to hand it over when they are finally outlawed. But I don't need a flak jacket, grenades, a bullet prrof car, etc. I may need crypto to keep my privacy, even though I believe in theory that it shouldn't be nessessary, but I don't need all the other bullshit (sorry if I'm stepping on anyone) 'cyber-survivalist' indicates. -j -- "Blah Blah Blah" ___________________________________________________________________ Jamie Lawrence <jamiel(a)sybase.com>

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Re: Detweiler clone at WS
by wcs＠anchor.ho.att.com 17 Dec '03

17 Dec '03

> Roy M. Silvernail says: > > > A BBS is a publication. The > > > 1st Amendment was specifically written to outlaw the British licensing of > > > publications. No risk. > > > > Until some case law comes about that recognizes this, It Just Ain't So. > > Right now, electronic publishing isn't recognized by the courts as > > publishing (because we don't kill trees, I suppose). > Cubby vs. CompuServe is at least the beginning of that recognition. Bill Celebrate Independence Day the traditional way - overthrow a government! :-)

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Re: What motivates crypto-folk?
by rah＠shipwright.com 17 Dec '03

17 Dec '03

At 11:45 AM 7/1/94 -0800, Jamie Lawrence wrote: >My own personal opinion is that waiting for governments to collapse >due to crypto and tech is gonna have you waiting a long, long time. God. What I do when the brain's offline. I'm looking at my wife's copy of this month's Harvard magazine, which is about, of all things, trees. It seems that the american chestnut used to be a great big tree. Remember the doggerel about the spreading chestnut tree and the smithy? Anyway, at the turn of the century an imported fungal disease killed all the chestnut trees to the ground. Someone in the article is quoted as saying "...chestnuts are continuing to sprout from the base and the tree is in the process of becoming a shrub." This apt metaphor is what I expect will happen to large organizations as a result of hyperdistributed (ubiquitous) computer networks and strong crypto. Of course, like the "expectation" that extraterrestrial life exists in the universe, it might as well be a religious tenent until we actually see it happen. Having political discussions like this one only gets us in the mood to make it happen if it's possible, but it certainly don't make it so. I don't think I could call myself a crypto-anarchist, even after that somewhat hardline paragraph. I call myself a "congenital republican". That's inconsistent enough to keep my friends and family happy, and myself gainfully employed. What I realy think is my own business. As usual, Tim is right. This really isn't crypto. It's just "about" crypto. >Jamie "Is a Mayist Like a Janist?" Lawrence > >-- >"Blah Blah Blah" >___________________________________________________________________ >Jamie Lawrence <jamiel(a)sybase.com> Bob "I ain't no Jainist, I just ate bugs(fleas?) for lunch" Hettinga ;-). ----------------- Robert Hettinga (rah(a)shipwright.com) "There is no difference between someone Shipwright Development Corporation who eats too little and sees Heaven and 44 Farquhar Street someone who drinks too much and sees Boston, MA 02331 USA snakes." -- Bertrand Russell (617) 323-7923

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Re: What motivates crypto-folk?
by jamiel＠sybase.com 17 Dec '03

17 Dec '03

At 12:38 PM 07/01/94 -0700, Timothy C. May wrote: >I'm also tired of them, and I don't spam folks who are liberals or >leftists. I've generally found that people's political views are >formed when they are of college age, and rarely change significantly >after that. Not sure why this is so, but I think it is. So that makes 2 things we agree on... :) And I think that you are right about college. Mine have taken minor changes (maybe that's because I haven't ever finished school), like on crypto for instance (I admit it... used to lean to the anti-side), but school choice does have greater significance than I think a lot of people give it credit for. >Just to be clear about this, in no way, shape or form am I just >"waiting for governments to collapse." I wasn't refering to you specifically, Tim. The folk on this list for (well, the most part) are a lot more active than the population at large (pat, pat). When I wrote that I was thinking of this little enclave of folks that used to frequent several lists that I was on and post enourmous tirades about how then the government shriveled up and died of it own accord everything was gonna be great and so on. Gimme a busy anarchist to an couch potato anything any day... >I'll make the charitable assumption that "I prefer doing something with >the tools at hand to dreaming" is not an insinuation that we >libertarians or crypto anarchists are idle dreamers. As above, I should have been more careful about the insinuation. Tim, Didn't know you did charity. ;) >The Jains eschew eating living things, while the Mayists *only* eat >freshly-killed meat. But you knew that. Wow, that makes three things... >--Klaus! von Future Prime -j -- "Blah Blah Blah" ___________________________________________________________________ Jamie Lawrence <jamiel(a)sybase.com>

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Re: Physical storage of key is the weakest link
by Matt Thomlinson 17 Dec '03

17 Dec '03

what does this mean, exactly? anything? thx, mattT ---------- From: Hal <hfinney(a)shell.portal.com> To: <cypherpunks(a)toad.com> Subject: Re: Physical storage of key is the weakest link Date: Friday, July 01, 1994 6:31PM Tim May writes: >Speculatively, knowing the passphrase-encrypted secret key may make it >easier to crack RSA; this is just a speculation. It is not yet even >been proven that RSA is a strong as factoring. i.e., we don't know for >sure that the RSA information provided as part of the protocol doesn't >in some way make the problem simpler than straight factoring of the >modulus. Here is a little-known fact. In fact, I had forgotten it myself until what Tim said reminded me. Your PGP secret key file is partially encrypted using IDEA keyed with the hash of your pass phrase. But some fields are left in the clear. In particular, the number of bits in p and q is left exposed, as is the number of bits in d, the decryption exponent. Now, this is not really a big deal. Usually with a 1024-bit key p and q will both be 512 bits long, so knowing this for sure doesn't add that much information. And I don't think that knowing the exact number of bits in the factors will help with the factoring when the two factors are about the same size. Nevertheless it does represent an information leak that many people may not be aware exists. One way an attacker might exploit this is as follows. Suppose he wants to do an exhaustive search of pass phrases. As Tim said, a lot of people may have ones which are easy to guess. How does he know when he's guessed correctly? The secret key has a checksum (in the clear). After decrypting all of d, p, q, and u, PGP accumulates a checksum as it does this and com- pares it with the checksum stored in the secret key. If they match, PGP (or the cracker) knows that he has used the right pass phrase. This requires decrypting all four of these numbers, a total of about 320 bytes. But he can do a provisional check much faster by using the in-the-clear lengths. Just decrypting the first byte of each MP number allows you to see immediately what the bit length of the resulting MP value will be since they are stored in MSB form. For the most extreme case, suppose the length of p were one more than a multiple of 8, say 505 bits. Now we decrypt the first part of p and see if the first byte of the decryption is exactly 1. If not, we can know immediately that we have the wrong pass phrase and move on without doing any more IDEA op- erations. This will immediately reject 255 out of 256 wrong pass phrases. I don't know how much of a speedup you would actually see from this; IDEA has a setup phase and you still have to run MD5 on each pass phrase. But possibly it could be significant. Hal Finney hfinney(a)shell.portal.com

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Re: Un-Documented Feature
by schirado＠lab.cc.wmich.edu 17 Dec '03

17 Dec '03

trollins(a)debbie.telos.com (Tom Rollins) writes: >PGP 2.6ui has an undocumented feature. > >When generating a Public/Secret key pair PGP documentaion shows >the command "pgp -kg" as the way to generate the keys. >I had posted about how pgp uses a small public key exponent >of 17 which is 5 bits. >It turns out that this is only the default setting. >An Un-Documented feature in PGP 2.6ui (I don't know about other >versions as I don't have source code for them) lets you specify >the number of bits in your public key exponent. >The command "pgp -kg keybits ebits" will let you specify this >public key exponent size. For example "pgp -kg 1024 256" will >generate a key with modulus of aprox 1024 bits and a public >key exponent of 256 bits rather than the 5 bit default. > >Too Bad pgp doesn't let you look at the public key exponent. >I had to write some code to see them. Questions: 1) In non-mathematical terms, if possible, what difference does this make in terms of security? 2) Does anyone know why is this undocumented? 3) What changes did you make? Sounds like it would be a well-received set of patches to be made public. (I'm well aware of the current arguments regarding algorithmic strength being no substitute for secure key management; I'm merely curious.)

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Re: Physical storage of key is the weakest link
by Matt Thomlinson 17 Dec '03

17 Dec '03

duh. sorry, guys. wow, that doesn't happen very often. a personal msg from me to the list. won't happen again. mt (phantom(a)u.washington.edu)

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Mac PGP 2.6 sig file
by lcottrell＠popmail.ucsd.edu 17 Dec '03

17 Dec '03

I have just unstuffed the Mac PGP archive I grabbed from MIT. Inside is a detached signature file. What file is a signature for? Is it for the binhex file, for the first archive, for the archive in the archive? Has anyone made this work? -------------------------------------------------- Lance Cottrell who does not speak for CASS/UCSD loki(a)nately.ucsd.edu PGP 2.3 key available by finger or server. "Love is a snowmobile racing across the tundra. Suddenly it flips over, pinning you underneath. At night the ice weasels come." --Nietzsche

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Credit-card PCs exist
by fnerd＠smds.com 17 Dec '03

17 Dec '03

I'm looking at an ad for "CARDIO 386," a PC in a thick card a little bigger than a credit card. It has a 236-pin connector with a full AT bus, VGA interface for video or LCD, IDE interface for hard disk, 1 parallel, 2 serial, keyboard, mouse and floppy interfaces. Up to 256K Rom and 4M DRAM. I don't see built-in SRAM or battery, but they have SRAM and flash cards as well as a PCMCIA interface. The point is that it's what developers and their tools are used to. You could run regular PGP on it, for instance. (That reminds me: does anyone know whether automatic teller machines are PCs inside?) S-MOS Systems of San Jose, CA. "A Seiko Epson Affiliate." and of which i am not an affiliate, -fnerd - - - - - - - - - - - - - - - spam is in the eye of the beholder (splat) -----BEGIN PGP SIGNATURE----- Version: 2.3a aKxB8nktcBAeQHabQP/d7yhWgpGZBIoIqII8cY9nG55HYHgvt3niQCVAgUBLMs3K ui6XaCZmKH68fOWYYySKAzPkXyfYKnOlzsIjp2tPEot1Q5A3/n54PBKrUDN9tHVz 3Ch466q9EKUuDulTU6OLsilzmRvQJn0EJhzd4pht6hSnC1R3seYNhUYhoJViCcCG sRjLQs4iVVM= =9wqs -----END PGP SIGNATURE-----

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Re: Password Difficulties
by smb＠research.att.com 17 Dec '03

17 Dec '03

Figure that each English character has 1.8 bits of entropy. (This is a conservative number, because it doesn't take into account case, spacing, or punctuation.) If I want a passphrase that will map into a 64-bit keyspace, I need at least a 35-chararcter phrase. Don't forget the difficulty of typing such a long phrase, with echoing turned off.

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