December 2003 - cypherpunks-legacy

Crypto Tech Reports
by baum＠newton.apple.com 17 Dec '03

17 Dec '03

The following technical reports are FTPable at ftp.cs.uow.edu.au pub/papers Cheers, >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>|<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Yuliang Zheng Email: yuliang(a)cs.uow.edu.au Centre for Comp Security Research Department of Computer Science Voice: +61 42 21 4331 (office) University of Wollongong +61 42 21 3859 (dept) Wollongong, NSW 2522 AUSTRALIA Fax: +61 42 21 4329 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>|<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Preprint No. 94-1 Y. Zheng ``Improved Public Key Cryptosystems Secure against Chosen Ciphertext Attacks'' ABSTRACT This note describes an improvement to the first two of the three public key cryptosystems proposed by Zheng and Seberry, which are provably secure against chosen ciphertext attacks. The improvement removes a shortcoming with the original cryptosystems, which occurs when they are used for both confidentiality and sender authentication purposes. Preprint No. 94-2 J. Seberry, X.M. Zhang and Y. Zheng ``Relationships Among Nonlinearity Criteria'' ABSTRACT An important question in designing cryptographic functions including substitution boxes (S-boxes) is the relationships among the various nonlinearity criteria each of which indicates the strength or weakness of a cryptographic function against a particular type of cryptanalytic attacks. In this paper we reveal, for the first time, interesting connections among the strict avalanche characteristics, differential characteristics, linear structures and nonlinearity of quadratic S-boxes. In addition, we show that our proof techniques allow us to treat in a unified fashion all quadratic permutations, regardless of the underlying construction methods. This greatly simplifies the proofs for a number of known results on nonlinearity characteristics of quadratic permutations. As a by-product, we obtain a negative answer to an open problem regarding the existence of differentially 2-uniform quadratic permutations on an even dimensional vector space. =========================================================================== Newsgroup Co-moderator: Richard Golding, Hewlett-Packard Laboratories compdoc-techreports-request(a)ftp.cse.ucsc.edu Be sure to send questions about specific reports to the poster, not to the newsgroup. ************************************************** * Allen J. Baum tel. (408)974-3385 * * Apple Computer, 20525 Mariani Ave, MS 305-3B * * Cupertino, CA 95014 baum(a)apple.com * **************************************************

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Big Brother Inside Stickers, V2.0
by Matt Thomlinson 17 Dec '03

17 Dec '03

To everyone that requested/was thinking of requesting the big brother inside postscript: The version I sent out individually this morning was buggy; the 'd' in "inside" filled in. (Too bad corel's screen image and postscript output isn't the same, huh? maybe they fixed that in v4.0?) I've re-exported it and the NEW version should be up for ftp sometime tonight at cpsr.org; Dave Banisar will announce its whereabouts. Sorry for the mixup. mt Matt Thomlinson Say no to the Wiretap Chip! University of Washington, Seattle, Washington. Internet: phantom(a)u.washington.edu phone: (206) 548-9804 PGP 2.2 key available via email or finger phantom(a)hardy.u.washington.edu

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Re: Detweiler abuse again
by W. Kinney 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- hughes(a)ah.com (Eric Hughes): > The automatic broadcast property of Usenet is profoundly broken for > the long run, since there is no upper bound on the amount of resources > required. More immediately, this property also requires a 100% One can only reach the conclusion that Usenet is broken if one assumes that the remailers _aren't_. The automatic broadcast property if Usenet is not a problem if you can always determine the source of a message. This isn't an argument against anonymity, but just saying it's a little backwards to say that Usenet has to be redesigned because it doesn't work with the remailers. Why not use technology to solve a technological problem? The difficulty here is that it is impossible for any one remailer operator to prevent someone, say LD, from using the remailer system. The best he can do is stop LD from using his site as an entry point. So why not introduce a little cooperation among operators? This can be accomplished without collusion of the sort that would break anonymity. Pretty much all the remailer operators are 'punks, right? If a critical mass of operators get together and agree to block a standardized set of sources and destinations, then that group of operators will have enough pull to force the other operators to toe the line. The trick is to block messages from remailer _operators_ who refuse to agree to behave as part of the community, effectively isolating the wildcats. An isolated remailer is useless. Should be easy enough to work out -- a posted alert PGP signed by any two remailer operators is immediately implemented, no questions asked. Remailer scripts should include blocking by source, destination, or _content_, as in posts on a certain subject to a certain newsgroup. This would allow blocking of a nutcase using encrypted hops to post to Usenet without having to collude and blow his anonymity. Just say "Sorry, due to abuse of the remailers, we're not going to forward messages about the creatures from Uranus using microwave mind-control any more". This is a complicated idea in a general case, but scanning for subject lines, for instance, could be implemented as easily as scanning for destinations. What we have now is a bunch of single remailers. It's a very small step to create a cooperative group of remailers, and it would provide avenues for solutions to a lot of the potential problems. This is not perfect, but it's better. tytso(a)ATHENA.MIT.EDU (Theodore Ts'o): > Lance is, unfortunately, pointing out some huge, gaping holes in the > current architecture of the Cypherpunks remailers. It would be good if LD is smart enough to know that you _chain_ remailers for anonymity. I think he wanted us to know it was him, and wanted to see whether or not Hal would blow his anonymity when it came down to it. -- Will -----BEGIN PGP SIGNATURE----- Version: 2.3 iQCVAgUBLWCOLPfv4TpIg2PxAQHOCgP9E2Q4R6ngHIeIv/IPePhcFqJgDaA8B4OO CDS0akeyVXZXMB5b5nCGY2Q0b52LcSHnzUlJ0N/o1COjVNLADNOlcF2k9BcBYUuC cqSWy1fJlx4lwd3P2kMgtk8v+pLHlVLJ4riopp2RXgLVfsesw8aJWOdSBf3bA7ft cBxNJhcI9t8= =BycG -----END PGP SIGNATURE-----

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oops
by Robert A. Hayden 17 Dec '03

17 Dec '03

Ok, sorry. Didn't know that L.D. wasn't on the list any more :-) ____ Robert A. Hayden <=> hayden(a)krypton.mankato.msus.edu \ /__ -=-=-=-=- <=> -=-=-=-=- \/ / Finger for Geek Code Info <=> In the United States, they \/ Finger for PGP 2.3a Public Key <=> first came for us in Colorado... -=-=-=-=-=-=-=- (GEEK CODE 1.0.1) GAT d- -p+(---) c++(++++) l++ u++ e+/* m++(*)@ s-/++ n-(---) h+(*) f+ g+ w++ t++ r++ y+(*)

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Detweiler abuse again
by hughes＠ah.com 17 Dec '03

17 Dec '03

My maxim for cases like Hal's monitoring of his remailer: Strengthen all parties. Therefore, we have two problems to solve. The user of the remailer got his anonymity blown, and the usenet groups got abused. A. User anonymity It has become very clear to me that the opponent model of universal network monitoring is not the first model that we should be deploying for. This is the worst case, and the worst case is the hardest to solve. The opponent here was logging by the service provider, and the technique was logging. We should ensure that we can defend against this opponent and this technique. Any email-based entry point into an anonymous messaging system will contain an identity-based address. Yet an IP-based entry point will only reveal the host. The lesson: Remailers ought to run server daemons. This has the happy side-effect of removing default email logging. It also will allow for IP forwarders to have some reason for use and development. B. usenet abuse The automatic broadcast property of Usenet is profoundly broken for the long run, since there is no upper bound on the amount of resources required. More immediately, this property also requires a 100% completely distributed salience filter in all the posters for newsgroup topicality to hold, that is, everybody has to stay on topic, no exceptions. Please. The feedback mechanism of bitching and moaning to sysadmins does not scale, however, especially when nodes spring up dedicated to technologically-enforced freedom of speech, nodes which completely ignore any particularities of content. In the long run, Usenet will have to move to some method of distributed moderation before widespread distribution. Since salience is determined by humans, humans will have to read messages before transmission. The scale of distribution may be wide. One path of development in support of remailers, therefore, has nothing to do with remailers as such but rather with the re-creation of the public forum which is suitable for anonymity. In the short run, anonymous mail should not be posted to newsgroups by parties unwilling to take the heat, both external flames and internal guilt. The operators of remailers who don't wish this should acquire lists of known mail-to-news gateways and then filter. The rest of the operators may wish to install their own gateways in the remailer as Eric Hollander has done. Eric

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re: LEAF, SS7
by m5＠vail.tivoli.com 17 Dec '03

17 Dec '03

It may be that traffic analysis of Clipper conversations is a question orthogonal to the switching system employed to establish circuits, but the question remains: does the presence of LEAF blocks on circuits simplify the task of traffic analysis? Methinks it does, particularly as the network gets more complicated. While it's tempting to think of this as a clever back-door way of getting some of the FBI "tap-o-rama" proposals implemented, it's not really interesting until nearly everybody is using a Clipper phone. Consider this little flight of fancy: what if, "in the interest of the privacy of the subscribers", Clipper hardware is installed right in each end-office switch? Thus, every phone call is Clipper encrypted as it passes through the network, even if I don't have a Clipper phone. It might even be that Clipper hardware could be installed right at the network interface. Isn't that nice, the phone company is going out of its way to safeguard my privacy. Only thing is, now every circuit I establish is tagged by an LEAF that identifies me... Oh well, enough paranoia for now. -- | GOOD TIME FOR MOVIE - GOING ||| Mike McNally <m5(a)tivoli.com> | | TAKE TWA TO CAIRO. ||| Tivoli Systems, Austin, TX: | | (actual fortune cookie) ||| "Like A Little Bit of Semi-Heaven" |

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I've got the big bro inside postscript
by Matt Thomlinson 17 Dec '03

17 Dec '03

send me mail if you'd like a copy; I assume it'll be up on the cpsr.org ftp site soon, but.. I hadn't previously released it, but I just made a dump from the .cdr file... mt (it is around 60k .ps, 28k .ps.Z). Matt Thomlinson Say no to the Wiretap Chip! University of Washington, Seattle, Washington. Internet: phantom(a)u.washington.edu phone: (206) 548-9804 PGP 2.2 key available via email or finger phantom(a)hardy.u.washington.edu

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Detweiler abuse again
by qwerty-remailer＠netcom.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Eric, could you repeat that in English, after those drugs wear off ;-)? >maxim, Strengthen all parties, opponent model of universal network >monitoring, identity-based, IP-based entry point, server daemons, >reason for use and development, profoundly broken for the long run, >100% completely distributed salience filter, newsgroup topicality, >everybody has to stay on topic, no exceptions. Please. No offense dude, honestly, you obviously are thinking on a great scale, very fast, but could you recapitulate your ideas in the morning so the rest of us can understand what you are trying to say? -=Xenon=- -----BEGIN PGP SIGNATURE----- Version: 2.3 iQCVAgUBLWAeKQSzG6zrQn1RAQHyjwP9F9GYwLQWvjs+Phd0kOsYQseCFjeH/jLj jbQNSLrpOnCm1+jL1hc8Ewv837Bvz/VDcc6Aw/exnemX/8SUw7sZ4V1by7tsKYc+ W2TZTWV0wmfSGyEmrZJrDXUc1issXwKbEgqPoAEbidLbu4ZuqJEbeciaPFb7R7h5 iIjE/3JlDM4= =loKk -----END PGP SIGNATURE-----

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Re: Clipper and Traffic Analysis
by jim＠bilbo.suite.com 17 Dec '03

17 Dec '03

> The reason I ask is, I have this sense that one reason the > government likes Clipper is that the Law Enforcement > Access Field enables agents to draw inferences about > who's talking to whom and what they're saying, even > without decrypting the actual communications. > Is it true that law enforcement can obtain phone records from the phone company simply by asking? Or do they need a supena(sp)? It would not surprise me in the least to hear someday that the government will allow law enforcement to record LEAFs without having to obtain a warrant for a wiretap. If Clipper becomes widespread, and most conversations are encrypted, the government might conveniently redefine the term "wiretap" to mean "decrypting a Clipper conversation". This would open it up for the government to continuously monitor and record LEAFs, probably via the soon to be mandated "wiretap" capabilities the FBI is pushing for. "After all, the LEAF is just the electronic equivalent of your phone record. This new definition of "wiretap" does not give law enforcement any new capabilities. Since the actual contents of the conversation are encrypted, there is no invasion of privicy. We're just trying to keep up with the latest technological advances." Jim_Miller(a)suite.com

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Detweiler remailer abuse
by qwerty＠netcom.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I can't take life seriously enough to censor old Larry. I can't take the IDEAL of the First Amendment lightly enough to do so either. And afterall, he wasn't the one who wrote that "Blacknet" blurb. I find it amusing to see uptight fuck-wads from specialized narrow minded Usenet groups yelling about someone sending something to their precious little group that upset them. Abuse away Larry. Show us that we really DO need dumb optical fibers between laptops instead of this tight-assed RFC standardized World Wide Wiretap we call our playground. We need a new net guys. -=Xenon=- <qwerty(a)netcom.com> -----BEGIN PGP SIGNATURE----- Version: 2.3 iQCVAgUBLWA4nQSzG6zrQn1RAQE1ygQAhOXiq/M11xIMNHxfdQUjgC+qBtWVx6IL WklpjXroNgb2mc4Xjqh2i/Pw4PZ39ecZYsdeIs7BViWw3FuAE+GAvqCAL8+tI5Hv Il5NxyNj/k8NqRhZY9YjWv7zzFZ9VKl1ifj4/eScEKcF6ZkbyaCrUAVJTXkJlcyx nTRfsFFYFLA= =Fbyt -----END PGP SIGNATURE-----

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