December 2003 - cypherpunks-legacy

Re: Hassles taking App. Crypt. to Taiwan?
by p.ruhnau＠jinxed.dinoco.de 17 Dec '03

17 Dec '03

On 21 Jan 96, TCMAY(a)GOT.NET wrote: > On the Taiwan side, though, they may wonder why you brought an > expensive > U.S.-printed copy when you get the special rice-paper edition of "Applied > Cryptography, 2nd Ed." for the equivalent of $2.25 in Taipei's book stalls. Can anybody tell me the addresses of taiwanese mail-order bookstores, please? MfG, Peter -- #define putc(c,fp) (--(fp)->_pc<0 ? (*(fp)->_pt)(c,fp) : (*(fp)->_cp++=c))

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DigiCash Ecash - 2 security topics
by Bryce 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- An entity calling itself "Marcel van der Peijl" <bigmac(a)digicash.com> is alleged to have written: > > (I wrote:) > > E.g. has there been a DigiCash response to Ian Goldberg's > > publication of a denial-of-service attack which operates by > > spending a coin with the same serial number as your victim's > > coin? > After discussing things with Ian we came up with several solutions. > One is encrypting more messages (which we will do in a next revision > of the protocol), the other is enabling ecash to work over ssl > servers. You may not see the answer directly in the list, but you > will see it in the next protocol revision. What kind of performance hit does this new encryption entail? (No additional performance hit if SSL does it, I know.) Are you considering having different protocols for SSL-protected transactions versus unprotected ones? Let me repeat something I said a couple of weeks ago: I suspect that the weakest point in DigiCash security is on the end-user's own harddrive. A malicious cracker could write a Trojan horse or even a virus which would steal the user's coins and send them to himself. Hm. Now that I think about it, if the user has a back-up copy of those coins then he can reveal their blinding factors to the bank after the theft, thus catching the thief! So the thief program would have to deposit those coins with the bank, make a new withdrawal (ouch!) and then steal the new coins. I'm not sure that anything can be done by DigiCash or by Ecash- issuing banks to prevent this, but I thought I'd mention it. (Hm. The program also has to steal the user's password in order to make the withdrawal.. This is getting to be a pretty smart program!) Regards, Bryce "Toys, Tools and Technologies" the Niche New Signal Consulting -- C++, Java, HTML, Ecash Bryce PGP sig follows -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Auto-signed under Unix with 'BAP' Easy-PGP v1.01 iQCVAwUBMQPWs/WZSllhfG25AQHv2gQAuJsZqQh+IF0vk8C2OY9zsvMlbqN0+GxN LinbZhWRDlqcRJ69dtzYDhbuvDphHuQYdNUJka5r3Bzplj5tim3sJ+wvEF2eiXTO vUSXrJ8DvnZPji+qEuv1Zs5D8gXdFs2ALsUbsDxQxVrVlcTbDKnz2EQel0apzqld VTV8CFvHaRY= =i3hX -----END PGP SIGNATURE-----

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Netscape + Verifone
by Perry E. Metzger 17 Dec '03

17 Dec '03

My pager delivers me selected miniaturized Reuters news stories. I just got one that reads: REDWOOD CITY, CA - Netscape Communications Corp. and Verifone Inc. will devise a system to make electronic payments on the internet more secure. Anyone know anything about this? I'm away from my normal sources of such things (like Bloomberg terminals)... .pm

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Lotus key breaking?
by Thomas Grant Edwards 17 Dec '03

17 Dec '03

Hmmm...how long is the single private key of Lotus Notes? Is it time to warm up the key-cracking net again? VTW Billwatch #33 said that: >LOTUS BLINKS IN INDUSTRY/NSA CRYPT STANDOFF ... >On Wed, Jan. 17th, 1996, Lotus announced that it had increased the key >length of its International version of the Lotus Notes product to 64 >bits. They did this by building in a back door for the Administration to >use to decrypt any international traffic that it might desire to read. >Although there are a lot of reasons why we think this is a terrible idea, >the first one that springs to mind is the fact that the one public key that >Lotus has embedded in all their software is a single point of failure >for every International Lotus user throughout the world. ... >You can find a copy of the Lotus press releases at >http://www.lotus.com

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ecash
by Juzzy 17 Dec '03

17 Dec '03

Hello, I'm new to this mailing list and i was wondering if someone could post me some information on ecash, what it is, and its implementation. Thank You Justin Walker

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Crypto comedy
by dmandl＠panix.com 17 Dec '03

17 Dec '03

During some free time over the holidays, I finally got around to HTML-izing a bunch of articles I've had published over the years. These are among the most riotously funny things ever written. However, one of these pieces may be of particular interest to cypherpunks, as it revolves around cryptography. Be warned that the piece has no scientific merit whatsoever, and even misuses some archaic crypto terms. I was aware of it at the time, but I knew that 99.9% of people would never notice. (This was six years ago, long before cryptography became hip.) The piece is called "Ching Chow's Hidden Agenda." (Ching Chow was a comic that used to appear in the New York Daily News.) That's: http://www.wfmu.org/~davem (choose the "Some things I've written" option). There's some other interesting stuff on my web pages as well, with equally little scientific merit. --Dave. -- Dave Mandl dmandl(a)panix.com http://www.wfmu.org/~davem

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Re: Ultimate Paranoia
by Lou Zirko 17 Dec '03

17 Dec '03

At 12:10 PM 1/22/96 +0100, Anonymous wrote: >Fellow Cypherpunks, > >I have been lurking around for some time and I have learned alot, But I have >a few questions that I either haven't seen posted or I've missed all together. > >I keep PGP stored on a removable hard drive and keep it under lock and >key when it's not in use. I write and encrypt messages on a stand-alone >computer, >that I only have access to. My passphrase is rather long and full of gibberish, >But I still fear the other things that I can not control. > >Does anyone make and sell a device that emits white and pink noise? > >How do you take the randomness collected from radation sensors to create >a truly random sample for creating a PGP key? > >Is there anything else that I might be missing besides lining the walls & >computer >in tin foil? :^) > >Thanks for your help! > >-Murphy > >-- There is a windows sond package that will generate brown, pink and white noise. The package is called Cool Edit. The currrent version is 1.52 and is available from : http://www.netzone.com/syntrillium/ Hope this helps. Lou Z. Lou Zirko (615)851-1057 Zystems lzirko(a)isdn.net "We're all bozos on this bus" - Nick Danger, Third Eye -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQCNAzBLJocAAAEEAMlDzYJPYq0pvfMuSiKU0Y65L2nJql+qEJHYGjO5Pys4prDw YW1ooPWaqrPQAy/eyqrM7I9KNFDCtmaPxtgcPw2oEDfc/w6cPkrVzvovKLfHQvtg V/hHUekptSf6j525omrVAoM9MxVL3sEGCjn9VrTeC3h9upkfntHOJeL88i2NAAUR tB5Mb3UgWmlya28gPHppcmtvbEBkYXRhdGVrLmNvbT4= =Qlxm -----END PGP PUBLIC KEY BLOCK-----

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No Subject
by owner-cypherpunks＠toad.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- In article <9601200326.AA09366(a)toad.com>, Peter Trei <trei(a)process.com> wrote: > > > If they're nasty, they'll check on the receiving side as well, to > > > ensure that the LEAF and/or the espionage-enabling key have not been > > > patched in the sending 'International' version. > > > > Nearly impossible. Why? Because they can only include the public key, > > and not the private key, of the GAK authority in the code. You can > > encrypt the three bytes of key, but it is very hard for a receiver > > other than the govvies to read them. There is no shared secret > > information or private information available, ergo, they can't check > > their LEAF equivalent. > > Think it through. [suggesting that Alice encrypts 24 bits of key under NSA's public key, Bob repeats calculation and checks that the two LEAFS are the same] > Thus, you can prevent a non-complying copy of Lotus from talking to > a complying copy of Lotus, which is one of the goals of the GAKers. No, you're wrong, the process you've described does not work. Note that RSA normally is used as probabilistic encryption: encrypt the same plaintext twice, and you'll likely get two different ciphertexts. Thus, if RSA is used in the normal probabilistic way, the receiver can't tell whether the sender was compliant. Now you might suggest that the sender should not include probabilistic padding, and use RSA deterministically, so that (somehow) the receiver can check whether those 24 bits are correct. That again won't work, since a third-party eavesdropper will be able to do a 2^24 brute force calculation to recover those 24 bits. There are complicated ways to prevent a non-compliant copy of Lotus from inter-operating with a compliant copy (as others on cypherpunks have kindly pointed out), but they are complicated, and would require a re-design of Lotus Notes' encryption module. Since the export version is interoperable with the non-export version, this would seem to require too much foresight and work to be very likely. In any event, I've heard that the export version of Lotus Notes 4 always sends a LEAF, but the receiver never checks it. So I think a simple binary patch to change the NSA's public key should work. P.S. So does anyone know how large the NSA's public LEAF key is? - --- [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 iQBFAwUBMQKzSyoZzwIn1bdtAQF/zAGAxODShPqrBQLsWzRVAkW7+jbVJidQIF5q 1Jyisn2EedTQoBLHnZD7ojnmws807XZK =bRAO -----END PGP SIGNATURE-----

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Re: More thoughts about digital postage (was Re: Digital postage and remailerabuse)
by shamrock＠netcom.com 17 Dec '03

17 Dec '03

At 8:42 1/22/96, Alan Bostick wrote: >People asked in earlier in this thread how remailers could issue digital >postage stamps without being able to know who is using which stamp issued. > >One obvious approach is to use blind signatures. Sure. That is the obvious approach. It also is, IMHO, by far the best. One minor problem is that the blind signature technology has been patented by its inventor, David Chaum the ower of DigiCash. You can't just write your own implementation. You also don't need to. Just use DigiCash's Ecash for postage. There is some work being done on a new MIME based remailer standard that would allow this to happen. At this time, the big problem seems to be keeping the message size constant between hops. See the remailer-operators list for the current discussion. -- Lucky Green <mailto:shamrock@netcom.com> PGP encrypted mail preferred.

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Re: DigiCash Ecash - 2 security topics
by shamrock＠netcom.com 17 Dec '03

17 Dec '03

At 11:26 1/22/96, Bryce wrote: >What kind of performance hit does this new encryption entail? >(No additional performance hit if SSL does it, I know.) Very little. >Are you considering having different protocols for SSL-protected >transactions versus unprotected ones? It isn't just an issue of SSL vs. unprotected. The new Ecash API that DigiCash is jointly designing with developers, will support two basic levels of operation. The first is similar to today's Ecash software. The client handles the transport. The second just generates the messages. Your application is responsible for getting them to where they should go. Presumably securely. >Let me repeat something I said a couple of weeks ago: I suspect >that the weakest point in DigiCash security is on the end-user's >own harddrive. A malicious cracker could write a Trojan horse >or even a virus which would steal the user's coins and send them >to himself. Given the amounts likely to be found on a drive, I doubt it would be worth the effort. -- Lucky Green <mailto:shamrock@netcom.com> PGP encrypted mail preferred.

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