December 2003 - cypherpunks-legacy

Re: Multiple symetric cyphers
by cactus＠seabsd.hks.net 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- - -----BEGIN PGP SIGNED MESSAGE----- In article <199501121623.IAA00846(a)largo.remailer.net>, Eric Hughes <eric(a)remailer.net> wrote: >I am assuming that it's unlikely that all of the ciphers will be >broken simultaneously. Quick reasoning note: For forward secrecy, it's unnecessary that the ciphers be broken simultaneously; just that they are broken in the span of time between encryption and the attack. - - -- Todd Masco | "life without caution/ the only worth living / love for a man/ cactus(a)hks.net | love for a woman/ love for the facts/ protectless" - A Rich Cactus' Homepage - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLxUnexNhgovrPB7dAQE5LwP+JYB/CW87wI8zdgaE64KHffcde/L6c7f9 nrC0AC5ljrKYgUyzDY0XFiDd5kHSp/wtwFeZeGkobihZqGnuHgh9R9wnPTgfrKM5 L+DBymQiHvT8LG+UwBCCNcRH0dDODYpvB3fJrYobvAzEfEazfuWDdYMZ/o4feBqT r2meoZryBxE= =8qyB - -----END PGP SIGNATURE----- - --- [This message has been signed by an auto-signing service. A valid signature means only that it has been received at the address corresponding to the signature and forwarded.] -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Gratis auto-signing service iQBFAwUBLxViPSoZzwIn1bdtAQFC4AF/aIdX8R43DwPV8sfpjzr7MBlS2dFM+kmW MnYjcGHaSCkkyZ9XjXnJ3QWtvTFiigyF =9w/Z -----END PGP SIGNATURE-----

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FBI and BLACKNET
by Syed Yusuf 17 Dec '03

17 Dec '03

I was just visited by the a humble servant of the FBI inquireing what I knew of BLACKNET. They apparently believe it's a possible network industrial sabbatoge (read Terrorism). Although the person I spoke to was quite cordial and even bought me lunch (that's the way to win me over) I must really question the intellegence (read IQ) and intellagence (read reconnasance) of his superiors. apparently whoever sent him his lead doesn't pay attention to the net enough to know Blacknet was a hoax, and why did it take since august for them to find me? I explained to him the differece between a Cyperpunk and a hacker explained what a joke it is to be prosicuting Mr. Zimmerman and why the Government is in the wrong for trying to limit encrytion strenght. Then I demonstrated the Internet and how to e-mail the prez and FTP speaches of the Prez :) (I know I know, act stupid so they volentere as much info as possible, he let too many things slip, but still If I had his job I'd be following up things like this too) --Syed Yusuf (Cypherpunk and proud of it damnit!)

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Re: analysis of RemailerNet
by jrochkin＠cs.oberlin.edu 17 Dec '03

17 Dec '03

At 8:57 AM 01/12/95, Wei Dai wrote: >Alice is sending mail to. After the first day, she can >eliminate about half of the remailer users from the list of possible >targets, because they, like the the random user above, >received a mail even though Alice didn't send one out during the >collection period of that batch. Now, since Eve can eliminate >on average half of the list every day, Bob will be the only person left on >that list after about (log base 2 of one million) = 20 days. > >Suppose Alice sent out some different numbers of cover e-mail: [...] > 3 log base 1 of 1,000,000 = infinity! Yeah, I think it made sense. Let me try to rephrase what you are saying in English rather then math, to see if it's still what you are saying. 1) Attacker Eve wants to figure out who Alice is sending mail to. 2) She can weed people out by noting 'collection periods' where Alice sends mail, but certain people don't receive any mail, and eventually arrive at Bob. 3) If Alice sends mail out in _ever_ collection period, perhaps just to the bit bucket, this method won't work, because there won't be any periods where Alice doesn't send mail out. Hmmm. The basic idea here is simply that you should send out lots of cover mail, at least one piece in every collection period, to prevent this kind of attack. Best, a random number of cover pieces, but at least one every collection period. Several thoughts: 1) If Alice and Bob are both corresponding with many people, things get more complicated. I tried to model it similarly to the way you modeled your simpler situation, but got confused quickly. This would be a good thing to look at. Alice sends and receives mail to several people other then Bob, and same with Bob. I'm not sure how this changes things, if at all. 2) In real life, it's more likely for an attacker to want to discover Alice knowing Bob then it is for him to want to discover Bob knowning Alice. It's Alice who is being anonymous here by using the anonymous RemailerNet, of course. I don't think this changes things either, but it's something to keep in mind.

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Re: Multiple symetric cyphers
by cactus＠seabsd.hks.net 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- - -----BEGIN PGP SIGNED MESSAGE----- In article <199501120502.VAA29808(a)largo.remailer.net>, Eric Hughes <eric(a)remailer.net> wrote: > From: cactus(a)seabsd.hks.net (L. Todd Masco) > > I'm wondering: would the strength be increased by using a randomly selected > symetric cypher? > >Strength is not right aspect. Global risk is reduced, simply because >the aggregate cost of a breach is reduced. Isn't it? If an attacker does not know what cipher is used and breaking each is computationally expensive (though not prohibitively so) doesn't that add extra complexity? IE, if cipher A, B, and C are attackable in large but not prohibitive time, wouldn't an attacker have to spend more cycles to break something that was randomly one of those? I agree that it's not a significantly large jump, but if an attacker has to go through all the possibilities for A, B, before breaking something in C, it seems that there's a small increase in strength (Not being argumentative, really... I understand that this increase in strength isn't enough to warrant any significant effort. Just want to clarify the answer in my mind). >But selecting a single cipher is just as much a fixed policy as a >randomly selected one is. Far better to let the user pick a policy, >both about sent and accepted ciphers. Sure. Ideally, a user could say "use A" or "use randomly A, C, or D" or even "use A_x(C_x) or B_x(D_y)". I'm not certain the "accept" is a great idea, but what the hell... any theoretical general system should have support for such a decision to be made, right? As failure modes multiply... > I guess this reduces to: do strong cyphers have "signatures" of some sort, > by which the type of encryption can be derived? > >If they do, they're likely not _strong_ ciphers. Great... that's the answer I was looking for, and what my gut feeling was. I'm trying to determine how much rope is too much for a first pass. Related: is there, in general or in any known specific cases, any loss of security in using sym. cipher A on ciphertext B (of another sym. cipher) with the same key? With different keys (I would think not, but I vaguely remember mention of something here long ago)? - - -- Todd Masco | "life without caution/ the only worth living / love for a man/ cactus(a)hks.net | love for a woman/ love for the facts/ protectless" - A Rich Cactus' Homepage - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLxSMSBNhgovrPB7dAQECKQP/fqXwOcRmH6Z5dm8fsDnFzkCNyy5bc7Os +/hWmyjlk6/qx2Ym0gvlIZaxMSVR68E1qQUaoiAaWY7SatskU8o6dZRI+SmON4NV qSZnBh/+TnQwcTK0c0N+4m3Y8GhIk0ERX9modZfadv15Q07yfP7MXEj4yRQOse6e WHmUg0WOhW4= =GedZ - -----END PGP SIGNATURE----- - --- [This message has been signed by an auto-signing service. A valid signature means only that it has been received at the address corresponding to the signature and forwarded.] -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Gratis auto-signing service iQBFAwUBLxTHISoZzwIn1bdtAQEUbAGAuX+ALOTHZkUd8vqsWzVZWKSKwnJ+03yW alp18VGBGaM4PLQWU0OAFmbBP8wUxBEz =U5tO -----END PGP SIGNATURE-----

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Re: How do I know if its encrypted?
by jrochkin＠cs.oberlin.edu 17 Dec '03

17 Dec '03

At 12:40 AM 01/12/95, Dale Harrison (AEGIS wrote: >Won't work! You can always embed an encrypted message in what 'looks' >like plaintext. A trivial example: Encrypt a message with a caesar >cypher, then build a story where the first char of each word maps to >each subsequent char from the encrypted text. At the cost of expanding >the size of the message by a factor of 5 to 10 you've hidden the >encrypted message in what looks like a letter to your mother (or a news >story in the NY Times, etc.) This is old technique. The context this was being discussed in, was trying to make _plaintext_ look like _ciphertext_. The operator of a data haven or remailer might hypothetically want to ensure that all text he dealt with was encrypted. So your method wouldn't do anything in that area. Unless you can think of a way to embed plaintext in ciphertext in such a way that it looks like ciphertext, and my guess is that any method that did that well would be sufficiently obscure as to be analagous to encryption for our purposes. Really bad encryption, with very little point, but still hidden text. Which is the real point, the operator doesn't want to deal with any text that isn't "hidden" in some way. Of course, we're not just dealing with text. So the scheme has got to be changed a bit so as to be able to detect unencrypted GIFs, and mu-law files, and as yet to be determined unknown files. I don't know enough about what's being talked about to know if this entropy detecting stuff will generalize to non text files. Cause we want to catch unencrypted GIFs too. [And doesn't compression alone do similar things to the entropy as encryption does, anyhow? If someone compresses their file with a good compression algorithm, as I understand it the non-randomness left will be pretty low. But it won't meet the needs we're discussing, I don't think.]

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Re: How do I know if its encrypted?
by jrochkin＠cs.oberlin.edu 17 Dec '03

17 Dec '03

At 12:01 PM 01/12/95, Hal wrote: >The idea of offsite storage doesn't seem that helpful since you can just >store the data on your own disk in encrypted form. Maybe if encryption >gets outlawed it would be useful, but then you can't use encryption to >communicate with the haven. Hmm. I post through a long anonymous remailer chain to an appropriate newsgroup: "I have made an archive of state secrets (or trade secrets, for that matter, or pornography), available on data haven Wherever. Ask to receieve the following file for a list of contents." Seems it could be useful. Especially if you had some way of extracting digicash payment from it, in an anonymous way. But even if you didn't, perhaps you want to make this info available as a public service. I sure as heck wouldn't want it sitting on a hard drive in my bedroom.

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Farewell for a bit
by dfloyd＠io.com 17 Dec '03

17 Dec '03

I need to work on the DH code, so I am unsubbing for a while. Please can the cheers, allright? ;-)

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Re: Reefer madness
by jrochkin＠cs.oberlin.edu 17 Dec '03

17 Dec '03

At 9:35 AM 01/12/95, Russell Nelson wrote: >misdemeanor. I spoke to Bob Penna, the legislative aide who >researched and wrote up the bill for Bill Sears. He realizes that the >Internet cannot reasonably be censored, and that the solution is to be >able to punish people who do it (hence the felony) and to educate I dont' find that particularly reassuring. "being able to punish people who do it," is ultimately going to have to consist of preventing non-GAK encryption, in the minds of the Gubmint. You can't punish them if you can't catch them, and you can't catch them if they use strong encryption. Well, in reality you still can catch them, after all no one can sexually assault anyone over the internet (yet, anyway). Sometime they've got to do something in person, and there's no encryption in a physical meeting, where everyone sees your TrueFace. But I'm not sure how much I trust the gubmint types to take this all into account, instead of just abolishing crypto on the typical four horsemen platform.

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Re: Reefer madness
by Mark Grant 17 Dec '03

17 Dec '03

On Thu, 12 Jan 1995, Russell Nelson wrote: > I really *don't* think that New York State plans to > ban encryption, not now and not over this issue anyway. His thrust is > 1) to have the legal authority to sufficiently punish someone who goes > after children (which they don't have now), and 2) to educate guardians > about the risks of untoward communications from adults to children. But what happens if, say, a minor is solicited for sex when they are pretending to be older than they are ? Or if the solicitation comes via a remailer ? Or a minor with a grudge fakes email to show that someone attempted to get them to agree to sex/picture-taking or whatever ? Once you pass laws making some forms of communication illegal, you're immediately getting into dodgy territory requiring is-a-person credentials and so on. That isn't neccesarily a problem if it's voluntary (e.g. your kids accounts might be set up to only accept mail from people who're certified to be under 18 or whatever), but governments are unlikely to do things that way. Mark

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Re: Chain and Shifting Remailer Addresses
by L. McCarthy 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Offshore Assets writes: > I use Hal Finney's 'Chain' a lot: Uh, I think you probably mean Lance Cottrell, not Hal -- unless Hal's also written a similar utility with an identical name, about which I haven't heard. > [...] But it won't PGP correctly with the Usura > and the Flame remailers because these two have e-mail addresses that > have changed and/or are different from the addresses specified in their > public keys (Usura, for instance, is now <usura(a)replay.com>, but this > is not the address given in its public key ID). Alex de Joode posted a copy of the usura key edited to reflect the domain name change to alt.privacy.anon-server. It's presumably on the keyservers.... Oh, and the flame remailer passed away with the closure of the jpunix remailer, as far as I can tell. (I vaguely recall something to the effect that sinet.org is/was registered as a subdomain of jpunix.com, but I might well be wrong.) Hope this helps. -L. Futplex McCarthy - --- [This message has been signed by an auto-signing service. A valid signature means only that it has been received at the address corresponding to the signature and forwarded.] -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Gratis auto-signing service iQBFAwUBLxWIfyoZzwIn1bdtAQHcYwF/alAsviWQvyzf4Qg1JR+G0l1sP3o6AGZN xvaxIZsKhhX03RNogflWZPBah3y8DnCa =aVDR -----END PGP SIGNATURE-----

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