December 2003 - cypherpunks-legacy

RE: One time pads and randomness?
by Blake Coverett 17 Dec '03

17 Dec '03

> I want to use a one time pad pased crypto system. I understand that the > randomness of the pad genorator is key to security(other than lossing the > keys). What I want to know is if I use a psuedo-RNG that maybe repeats its > self every 1000 characters and use it to only encrypt messagase that are > 100's of charaters long, will this be a major security risk? I'm afraid you've fallen into one of the standard traps. A PRNG can *not* make a OTP no matter how you use it. The total amount of entropy in a PRNG is the amount of entropy in the seed you use to key it. All the other bits are directly derived from that seed. A true OTP is completely secure from an information-theory point of view because every byte has a full eight bits of entropy. A PRNG can never have this. Having said all this, it is possible to make a good cipher from a PRNG. RC4, for example, is exactly that and the variable sized key is the seed for the PRNG. It is however very difficult to come up with a good algorithm for that cryptographically sound PRNG and you would be much further ahead to use an existing one rather that trying to roll your own. > Say I create a 1 million character one time pad that passes all of the > randomness tests. It is "truely random". I place it on two computers. Now > when these two computers want to send email computer "A" grabs a chunk of the > one time pad starting at a random point and encrypts it. It labels the email > with the random starting point and sends it to "B". There "B" moves to the > random point and begins decryption. During to process both computers mark > that section of the OTP used so that they don't retransmit with it. I realize > this has a limited amount of messages before it is used up. But would this be > secure? Any suggestions, complaints, big gapping holes I missed? I don't see anything wrong as such, but there is nothing to be gained either. If your random data is real OTP material there is no need to skip to a random byte within it, just start at the beginning and use it in sequence. If your random data is the output of a PRNG like the above then random starting point doesn't buy you much additional security because the entire set of keying material can be recreated from the seed. It may increase the work-factor of searching for the key, but it also imposes the practical problem of keeping all that keying material secure. More importantly don't confuse statistically random with cryptographically random. Just because a bunch of bits passes all the randomness test you can think of doesn't mean it contains 100% entropy. Consider the digits of an irrational number like sqrt(2) or pi, the digits appear statistically random but they can be recreated from just a tiny bit of knowledge. A good litmus test is to ask yourself if there is any way you can reproduce those bits. If there is, they aren't a one time pad. (Of course even if you can't it doesn't mean they are good. :-) regards, -Blake

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mailing list
by roamer.fau 17 Dec '03

17 Dec '03

Please place me on your mailing list. Thank You, Mark

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Re: [Fwd: Re: Victory Party]
by dlv＠bwalk.dm.com 17 Dec '03

17 Dec '03

Dale Thorn <dthorn(a)gte.net> writes: > aga wrote: > > Date: Sat, 18 Jan 1997 13:34:37 GMT > > On Sat, 18 Jan 1997, SB wrote: > > From: J Durbin <slothrop(a)poisson.com> > > > Forward on the good Dr. Vulis from ne.internet.services. > > > Newsgroups: ne.internet.services, alt.fan.speedbump, alt.god.grubor > > > Steve Subject: Re: Victory Party > > > hannigan(a)shore.net (Martin Hannigan) wrote: > > >Steve/Grubby/Vulis/Aga: You can come too. Of course. > > > The Cypherpunks mailing list people invited Vulis to come speak > > at one of their CA meetings. They even offered to pay for his airfare > > and lodging, but he was too afraid to show up. > > What a coward, just like Boursy and Grubor. > > > Hey you fucker; you pay my expenses and I will come. > > You get a one hour lecture and one hour of questions and > > answers afterward. Everybody gets frisked for guns at the door, > > since we do not trust some of those cypherpunks. > > Picture the typical cypherpunk (especially Sandfort, who organized the > whole thing): Old, out of shape, ignorant, lonely, perverted, ugly, > etc. etc. Dr. Vulis actually brightened up their "life" for a few > moments, then, when he didn't take the bait for the roast, they felt > rejected, like a love spurned. It's so transparent. It just wasn't worth the time. I found F2F contact with the likes of Hughes and Gilmore pretty boring and unproductive. But if Dr. Grubor wishes to address a Cypherpunks meating, and expose them as a bunch of homosexual censors, I think it would be a neat idea. --- Dr.Dimitri Vulis KOTM Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps

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Re: microcurrency: Netscape vs. Microsoft
by Hal Finney 17 Dec '03

17 Dec '03

From: "Vladimir Z. Nuri" <vznuri(a)netcom.com> > I predict that microcurrency will not catch on in a big way > until it is integrated with browsers, and when it is, it > will be adopted in an insanely large rush like the way > the web itself caught on with the GUI (and was mostly comatose > before it). > [...] > notice how much crypto really caught on when Netscape > incorporated it, and how this action alone did more for > the proliferation of crypto in cyberspace, almost, than > all prior efforts combined. I think that microcurrency > will be unleashed in a very similar way. I assume you are referring to secure web connections via SSL in talking about crypto. In that case there was a very strong pent up demand for the service. Customers were afraid to send credit card numbers and other personal information across the web. Sellers were pressuring the net server companies to do something to quell these concerns so on-line selling could succeed. Netscape did it, and in the grand tradition of the net, implementation beat design and SSL defeated SHTTP. In its early versions SSL had a lot of problems but it was a good enough solution for what it needed to be. The question is whether there is similar market demand for pay per view web pages. Do web service operators think they can offer value added services which will motivate customers to click through the for-pay link? Maybe porn would be a good initial market. There are so many sites where you've got to sign up ahead of time for $20 or so for a month's membership. This is a considerable barrier. But if you could just take a peek for $.50 there would be a lot of people interested. Porn is what started the VCR market before it later "went respectable", so maybe the same thing could happen here. I know that a lot of the initial vendors with First Virtual were selling racy pictures, although I think the company has taken steps to reduce their association with that market. This is not exactly the microcurrency that Vladimir is talking about but it would be a good model for integrating some payment system with a browser and it could serve as the foundation for other for-pay pages with lower fees. There is also the issue of sellers learning to use the various payment systems which are out there. Here again if Netscape and Microsoft would just pick one then everyone could standardize on it, which would increase acceptance a great deal. Ecash as it is implemented now has the problem that the customer has to open a special bank account. What you need is a payment system where you can use your existing VISA card and withdraw cash against it into your electronic wallet. This is pretty close to the FV model but their payment system is somewhat clumsy. I haven't followed the electronic payment market closely for the last couple of years. Are there any payment systems which look like good candidates for integration with browsers? Hal

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Announcing On Line Tax Tips
by GJDCPA＠aol.com 17 Dec '03

17 Dec '03

Hello,^Morons, January 17, 1997 Subject: Tax Tips and Important Due Date Reminder We are pleased to announce our site at http://www.gjdcpa.com. The purpose of our website is to provide information for the taxpaying public to assist you with your 1996 income tax return preparation.

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Cheap CyberShots
by Toto 17 Dec '03

17 Dec '03

In the interests of upgrading the quality of cheap shots in CyberSpace, I thought I would pass along the following as an example of how to 'finesse' a cheap shot. > Shouting Ground Technologies, Inc. is concerned about the increased > abuse of the internet with "spamming". In this instance, we find > ourselves in a dilemma. > * We do not condone any improper use of the internet, including > spamming. > * We respect the right of privacy of individuals, and the right > to conduct lawful business unhindered. ... > In the past few days we've received a lot of complaints about the > inappropriate messages. Several people have demanded that we take > immediate action. A couple were very critical that we did not > cut their internet access immediately. ... > So people are in effect suggesting that we > * Unilaterally violate the terms of their service contract, subjecting > us to liability for their lost business. > * Violate their right to privacy by filtering and reading all of > their e-mail and news traffic. > Presumably we would have the same culpability for all of our clients, > so we'd have to read everybody's e-mail before passing it on. We > suspect that anybody that wants to be treated that way already > has service with Prodigy.

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Re: Get me off this fucking list, or else.... (fwd)
by Bill Stewart 17 Dec '03

17 Dec '03

Either a) You don't follow directions very well (since you're still on the list, and since the software works just fine for people who can follow directions or consider spelling to be unimportant), or b) The mailing list daemon is broken (happens sometimes, but usually that gives you no traffic), or c) The mail you're sending doesn't have your correct headers on it (e.g. looks like it's from res(a)pc43.unidyne.uni.pt instead of res(a)unidyne.uni.pt) in which case you may need human help, or d) Somebody doesn't like you and subscribed you to the list because it's well-known to be a high-volume mailing list, and they keep subscribing you after you unsubscribe, in which case harassing the 1300+ people who _do_ want to be on the list is not a good thing to do. So send mail to majordomo(a)toad.com, saying "help" and RFTM. At 04:31 PM 1/17/97 +0000, Rodrigo Espirito Santo wrote: > > >---------- Forwarded message ---------- >Date: Fri, 17 Jan 1997 16:30:25 +0000 (GMT) >From: Rodrigo Espirito Santo <res(a)unidyne.uni.pt> >To: cypherpunks(a)toad.com >Cc: cypherpunks(a)toad.com >Subject: Get me off this fucking list, or else.... > >Hey you dumb asses, i tried to unsubscribe this list in the correct way >but you guys don't know SHIT about this!!!!1 >If you don't get me out now i'll subscribe each and every one of you to >some goddamn gay and lesbiann and freak mailing list!!!!!! >get me out!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > > > > # Thanks; Bill # Bill Stewart, +1-415-442-2215 stewarts(a)ix.netcom.com # You can get PGP outside the US at ftp.ox.ac.uk/pub/crypto/pgp # (If this is a mailing list, please Cc: me on replies. Thanks.)

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Internet Message
by Diode 17 Dec '03

17 Dec '03

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No Subject
by T. O'Brien 17 Dec '03

17 Dec '03

Unsubscribe

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Re: Newt's phone calls
by paul＠fatmans.demon.co.uk 17 Dec '03

17 Dec '03

> > GSM includes A5 encryption here, so basically the whole design is worked out > - all you'd have to do is rip out the A5 chip and replace with a decent > encryption system. Anyone know how modular the design is, for instance if > it would be possible to give a GSM A5 based cell phone a crypto upgrade > using published electrical interface standards? (I want one of those - > Nokia phone with IDEA + 2048 bit RSA signatures + DH forward secrecy!) My guess is that this would not work. Does anyone know if when you use a GSM phone to call a landline number the cellphone<-> base station trafic is encrypted??? my guess is that only when you call GSM to GSM is the trafic encrypted and even then I would imagine each phone agrees a key with the base station for the network then the trafic between the base stations is cleartext. The only way, if this were the case, would be to write the code so that the headers and other network information like SIM ID number etc... were cleartext or just A5 to the network as standard and only the actual speech data was encrypted under something stronger. This approach could become troublesome, if I have time I`ll get hold of some GSM specifications and look at it more closely. Datacomms Technologies web authoring and data security Paul Bradley, Paul(a)fatmans.demon.co.uk Paul(a)crypto.uk.eu.org, Paul(a)cryptography.uk.eu.org Http://www.cryptography.home.ml.org/ Email for PGP public key, ID: 5BBFAEB1 "Don`t forget to mount a scratch monkey"

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