December 2003 - cypherpunks-legacy

Re: [crypto] crypto-protocols for trading card games
by David F. Ogren 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- > On Wed, 29 May 1996, Simon Spero wrote: > > > Design a set of crypto protocols to support the issuing, trading, > > and playing of such card games in real time (100ms compute time > > per move) > > I'd been thinking about it from the opposite point of view: make up > a card game (possibly electronic, like what you're proposing) that > acts as intro to crypto for the untamed hordes of game players. > I've had similar ideas, but there are snags. Card playing via encryption techniques is a great idea in theory, but in reality the technical requirements often prevent implementation. Think of the requirements of this system: 1. Cards must be transferrable. 2. Cards must not be duplicated by anyone other than the game company. 3. Cards must be able to be randomly shuffled. (Since most trading card games are two-player games our task is simplified greatly.) Here is one possible algorithm, and some of its weaknesses. The game company generates a master public key pair with which it will sign all game cards. Each player generates a public key pair to verify his identity. Each card is composed of the following fields: A serial number, so that each card is unique. A public key generated by that the owner as a proof of indentity. (Each card owned by a player will have the same public key.) The name of the card and (optionally) a desception of its effects. Each card is then signed using the game company's secret key. For each game both partners generate a public key pair. Alice then signs each card in her deck with the public key she generated for this game and then transmits the cards (in a random order) to Bob. Bob does the same thing for his deck. Each time Alice needs a card, Bob selects one of Alice's encrypted cards and Alice decrypts it. As an additional measure to determine that Bob's cards are genuine, Alice sends Bob a random string and asks that he sign it with the secret key that matches the indentity-verifying public key on his cards. If Bob can return a signed version of that string, the ownership of his cards is verified. This indentity verifying routine can be conducted as soon as Bob's first card is revealed. Bob of course, conducts the same procedure for Alice after she plays her first card. After the game is over (or Alice's deck needs to be reshuffled), she reveals her secret key and Bob verifies that her cards are genuine and that she played fairly. Advantages: This system prevents anyone other than the game company from duplicating cards (each card has a unique serial number), and from copying other people's cards (each card has an indentifying public key). Any cheating can be discovered at the end of the game. Bob knows the order in which he selected Alice's encrypted cards. After the game, when Alice hands over her game-session secret key, he can check to make sure that Alice revealed her cards in the order he selected them. Only a reasonably amount of encryption/decryption is required. Most importantly only one key per player needs to be generated for each shuffle. During play only decryption is required. In other words, a modicum of set up is required, but once play begins the decryption shouldn't slow the program down appreciably. Disadvantages: The entire integrity of the system relies on the security of the game company's key pair. If the secret key is comprimised, either by a disloyal employee or by crytographic techniques, all cards in existence must be recreated. Cards are not transferrable. In order to make cards transferrable the game company must be able to invalidate cards which have been traded to others. In other words if Alice wants to give a cards to Bob she must: 1. Contact the game company and tell them she wants to give the card to Bob. 2. The game company must issue a new card to Bob with a new serial number and with Bob's public key rather than Alice's. 3. The game company must invalidate Alice's old card. Since there is no way that the game company can make sure all copies of the card have been destroyed it must create a "invalid serial number list" and have the players dial into that list everytime the game is played. Since step 3 is so costly to implement, I think it is unlikely that a cryptography-based trading card game will have tradable cards. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMay5ZvBB6nnGJuMRAQHYFAQAl/PwCB0U/rQfjNgdoeLNpo9TyPAdebhT FWjE44zjTmr6Cbl6S5D9QsqLub6eDI5DsXhD+w4Tipjn9/GZwQtFpEORx9MeAUWh 9TCtcDY4Tn5d8aNwtVikHt971uW6ROU7qWikIDipxotWtTscl8NESZbgmZqGOBWW 4VzGRMuIr1E= =bXqs -----END PGP SIGNATURE----- -- David F. Ogren ogren(a)concentric.net (alternate address: dfogren(a)msn.com) PGP Key ID: 0xC626E311 PGP Key Fingerprint: 24 23 CD 15 BF 8D D1 DE 81 71 84 C8 2C E0 4B 01 (public key available via server or by sending a message to ogren(a)concentric.net with a subject of GETPGPKEY)

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Broken Nymserver
by John A. Perry 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Hello Everyone, It turns out that the nym server at nymrod(a)nym.jpunix.com was slightly broken. My tests indicate that it is fully functional now. I apologize for the inconvenience. John Perry - KG5RG - perry(a)alpha.jpunix.com - PGP-encrypted e-mail welcome! WWW - http://www.jpunix.com PGP 2.62 key for perry(a)jpunix.com is on the keyservers. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMayhBlOTpEThrthvAQH3NwP/fF8SMTlV+LkaeyTz0YrWcY3wfeNaTkV/ u5JATy0yRgW/U/l6KsxI5mc2onVD5em2+srlvqb9JkLcQ8PTQWRSULwRpFO8rDvI fEic0UBdObt8QpacbNUgWJeNfXzbgYfv6Po72fci3aWWBc6RLuLC/uAnYv4VaNej IPyui2isWT0= =PCKi -----END PGP SIGNATURE-----

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Where does your data want to go today?
by Marshall Clow 17 Dec '03

17 Dec '03

>From <http://www.pcweek.com/news/0527/27stor.html>: >Helping pave the way toward cost-effective disaster recovery >systems, MCI Communications Corp. this week will join a growing >number of providers offering file backup and storage over the >Internet. [snip] >MCI and Connected house data on servers at two mirrored sites. >Both companies are adding an extra dimension of security over the >Internet by encrypting data. > >MCI's networkMCI Backup software, for Windows 95 or 3.x, will >scan a file for viruses, encrypt it using an RSA Data Security Inc. >public key and compress it before it is uploaded onto MCI's Internet >backbone network to a secure storage facility, said MCI officials in >Atlanta. [snip] Some comments (off the top of my head): * What kind of encryption? [The article says RSA. ] How big is the key? * Why encrypt before compression? If the encryption is any good, then the encrypted data won't compress much at all. However, compression before encryption has its own problems. * Who does the key management (if any)? * Does MCI store copies of the keys used? * How does MCI authenticate users who request copies of files, and do they then return them encrypted or as plaintext? If encrypted, how does the recepient decryt the files? (He/she just had a disk crash, and this is their backup medium, remember?) I looked on MCI's web site <http://www.mci.com>, but couldn't find anything. Besides, it's slower than sludge. [ 90 secs/page over my 128K link. :-( ] -- Marshall Marshall Clow Aladdin Systems <mailto:mclow@mailhost2.csusm.edu> "We don't have to take it; never have, never will. Gonna shake it, gonna break it; let's forget it: better still" --The Who, "Tommy"

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Update on CDA and copyright (5/29/96)
by Declan McCullagh 17 Dec '03

17 Dec '03

ON THE CDA: Folks involved in the case expect a decision within the next week from the Philadelphia three-judge panel hearing our challenge to the CDA. The DoJ has a few weeks to appeal to the Supreme Court if they lose. -------------------------------------------------------------------------- ON COPYRIGHT: Regarding the online copyright legislation, there's plenty of action on the Hill -- and contrary to what I thought a week ago, there's even a fighting chance that this bill will pass this year. So far, full Senate judiciary and the House judiciary intellectual property subcommittee have held hearings. The House has taken the lead here, and the tentative date for the subcommittee markup of HR2441 is June 5. (It was to have been last week, but was cancelled at the last minute when no agreement was reached.) The Senate seems to be waiting to see what the House does before making any sudden moves. General feeling is that the legislation was on a fast schedule but has been slowed down considerably because of ongoing controvery over OSP liability and (especially) section 1201. The big snarl is over 1201, and some alliances of convenience are breaking down. More to the point, libraries are finally mobilizing grassroots opposition. Brock has a piece about this in a recent Muckraker on HotWired. (I'm hundreds of messages behind on cypherpunks so if you reply to this please copy me.) -Declan

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Re: Ok, what about PGP (was: MD5 collisions)
by wlkngowl＠unix.asb.com 17 Dec '03

17 Dec '03

I poked around the pgp.h and pgformat.txt files in the PGP 2.6.2 distribution. There *are* designator bytes for the hash (and cipher) algorithms, hash size, etc. It seems quite doable to add support for SHA-1 signatures (and possibly key generation for encrypting secret keys?). Adding 3DES (and maybe Luby-Rackoff-SHA, assuming it hasn't been cracked recently at the Fast Software Conf.... more info?!?) would be nifty too... unless, of course, there's meaning to the Real Soon Now that PGP3 folx claim. I d work on the hack now (and just might...) but I'm stuck stranded in the United States. :( Rob.

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Re: Where does your data want to go today?
by droelke＠rdxsunhost.aud.alcatel.com 17 Dec '03

17 Dec '03

> > >From <http://www.pcweek.com/news/0527/27stor.html>: > > >Helping pave the way toward cost-effective disaster recovery > >systems, MCI Communications Corp. this week will join a growing > >number of providers offering file backup and storage over the > >Internet. > [snip] > > >MCI and Connected house data on servers at two mirrored sites. > >Both companies are adding an extra dimension of security over the > >Internet by encrypting data. > > > >MCI's networkMCI Backup software, for Windows 95 or 3.x, will > >scan a file for viruses, encrypt it using an RSA Data Security Inc. > >public key and compress it before it is uploaded onto MCI's Internet > >backbone network to a secure storage facility, said MCI officials in > >Atlanta. > [snip] > > > Some comments (off the top of my head): > > * What kind of encryption? [The article says RSA. ] How big is the key? Web page, and sign-up email doesn't say... > * Why encrypt before compression? If the encryption is any good, then the > encrypted data won't compress much at all. However, compression before > encryption has its own problems. This is just confusing wording I am sure - marketing/press-release people rarely get the details right. I would guess, that in order it is scanned, compressed, and then encrypted. Nothing else makes sense. > * Who does the key management (if any)? > * Does MCI store copies of the keys used? > * How does MCI authenticate users who request copies of files, and do they > then return them encrypted or as plaintext? If encrypted, how does the > recepient decryt the files? (He/she just had a disk crash, and this is > their backup medium, remember?) These are all good questions.... > I looked on MCI's web site <http://www.mci.com>, but couldn't find > anything. Besides, it's slower than sludge. [ 90 secs/page over my 128K > link. :-( ] http://www.mci.com/productview/framelements/backupindex.shtml (probably need netscape2 for this.) I requested to be a beta-test member and got confirmation email. I guess I'll wait until they contact me "early this summer" and see what their software does.... Dan ------------------------------------------------------------------ Dan Oelke Alcatel Network Systems droelke(a)aud.alcatel.com Richardson, TX

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Re: WSJ on "IRS-bashing"
by tcmay＠got.net 17 Dec '03

17 Dec '03

At 3:36 PM 5/29/96, geeman(a)best.com wrote: >According to WSJ, Leslie B. Samuels, "Treasury's top tax-policy official" >says that "IRS-bashing is 'counterproductive and harmful'" -- and that >"destructive rhetoric ... hurts the tax system and society" [elisions are >the WSJ's] > >What if a the CDA grew little by little by little until it covered >statements deemed "destructive rhetoric" .... hmmm. I mean after all, if >it harms society....! If the CDA is upheld by the Supreme Court, which would surprise me, then "free speech" as we know it is gone completely. By the way, it's _already_ the case that "hurtful speech" can be prosecuted as a civil rights violation of a class of persons. If I refer to women as "bitches and hoes" ("hoe" = "whore," in certain American dialects) I am, as I understand things, technically in violation of various laws which outlaw the repression, subjugation, marginalization, and encheferation of women and other colored people. (Oh, I can say these things in the privacy of my home without fear of reprisal by the State, or even in small groups. But if I say this in public, or in a company, or in many other fora, look out!) Liberty has been given away for several decades in this country. --Tim May Boycott "Big Brother Inside" software! We got computers, we're tapping phone lines, we know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Licensed Ontologist | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."

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[SF Bay Area] A talk on Pari by Carl Hansen
by stevenw＠best.com 17 Dec '03

17 Dec '03

Seen on the net: Pari talk by Carl Hansen Monday, June 10 from 7:30 pm to 9 pm BMUG, 2055 Center Street, Berkeley Carl will give an introductory talk on Pari, software that supports arbitrary precision arithmetic and includes many function for doing number theory. He will compare it to other math software and show the special features of this program, including how Pari can be used as a cryptographers workbench. This presentation will be at the BMUG office at 2055 Center Street in Berkeley. The office is near the north west corner of Center Street and Shattuck Ave. which is half a block from the Berkeley BART station. Driving directions: Take the University exit off 80. Head east on University toward the UC Berkeley campus. Turn right at Shattuck (McDonalds will be at the corner.) Go 2 blocks. Turn right on Center and look for parking. I recommend the parking garage on the left, as the one on the right may close at 8 pm. For more information on the Berkeley Macintosh Users Group (BMUG) Mathematics Special Interest Group (SIG), contact: Nancy Blachman Variable Symbols, Inc. 6537 Chabot Road Oakland, CA 94618-1618 Email: nb(a)cs.stanford.edu nb(a)eeyore.stanford.edu Fax: 510 652 8461 Telephone: 510 652 8462 ------------------------------------------------------------------------- Steven Weller | Technology (n): | | A substitute for adulthood. stevenw(a)best.com | Popular with middle-aged men.

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Re: Clipper III analysis
by tcmay＠got.net 17 Dec '03

17 Dec '03

At 5:54 AM 5/29/96, jonathon wrote: > A good Questioned Document Examiner will be able to demonstrate > that the signed document in question was not authored by Joe > Blow, even if it contains his digital signature. I was of course talking about digital signatures, not handwritten signatures. I would be very interested to hear how a "Questioned Document Examiner" can possibly determine that a digital signature was not applied by a particular person. --Tim May Boycott "Big Brother Inside" software! We got computers, we're tapping phone lines, we know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Licensed Ontologist | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."

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Subpoenaed for Deposition
by skaplin＠iaxs.net 17 Dec '03

17 Dec '03

Forwarded from alt.religion.scientology ----------------------------------------------- >From: "Homer W. Smith" <homer(a)light.lightlink.com> >Subject: Subpoenaed for Deposition >Date: Wed, 29 May 1996 14:03:47 -0400 >Organization: ART MATRIX - LIGHTLINK >Lines: 12 >Distribution: inet >Message-ID: <Pine.SUN.3.91.960529135938.4049A-100000(a)light.lightlink.com> >NNTP-Posting-Host: light.lightlink.com >Mime-Version: 1.0 >Content-Type: TEXT/PLAIN; charset=US-ASCII >To: Remailer Operators Network <reop-l(a)cornell.edu> >cc: Multiple recipients of list IAP <IAP(a)VMA.CC.ND.EDU> I have received a subpoena to be deposed by the Church of Scientology concerning the posting of Scamizdat #3 through the Free Zone Remailer on April 1st, 1995. Homer ------------------------------------------------------------------------------ Homer Wilson Smith News, Web, Telnet Art Matrix - Lightlink (607) 277-0959 SunOS 4.1.4 Sparc 20 Internet Access, Ithaca NY homer(a)lightlink.com info(a)lightlink.com http://www.lightlink.com --- Never play cards with a man called Doc. Fuck Exon - Fuck The CDA - Fuck Scientology - Fuck Dianetics - Fuck Congress Fuck The President - Fuck Obsenity - Fuck Democrats - Fuck Republicans Support Freedom Of Expression!

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