December 2003 - cypherpunks-legacy

Re: NYT article
by joshua geller 17 Dec '03

17 Dec '03

> joshua geller says: > > an interesting commercial product might be software to > > do blaze's trick.... > You can't build it -- the EES is not available as an algorithmic > specification to the public -- only as hardware. quite true. I was mistaken. josh

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Re: LEAF forgery
by VACCINIA＠UNCVX1.OIT.UNC.EDU 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Perry wrote about Matt Blaze's Awesome new hack: >Matt Blaze should be commended for finding such a big hole. As with most >such ideas, its obvious in retrospect but took some good thought to come >up with. It is indeed a great achievement to best the NSA at its own game. This hack allows secure transmission and closes the LEAF backdoor. However, this only strengthens my belief that they don't really need this LEAF access, can you say trapdoor? I still wouldn't be sending anything I wanted to keep a secret using TESSERA, even with a newly generated LEAF field. I'd wager that Matt wouldn't either. Scott G. Morham !The First, Vaccinia(a)uncvx1.oit.unc.edu ! Second PGP Public Keys by Request ! and Third Levels ! of Information Storage and Retrieval !DNA, ! Biological Neural Nets, ! Cyberspace -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLe6rez2paOMjHHAhAQGPyAP+PJwI4Wd6C72u1hEAqSgdIGigT2dcPjR9 12Z3/dE+GBFebt3SSXxbo9FC5v5BqyIX4mHq1LwgN9eSQIpVTEGYuB3m+RkMXVS6 mApDYkzaXE0E/vdYkTsPsn6UvePu91rxtfM2gCSPgc6Ex88UHV4E2AGN0Jfn2WRK NyyoN68bOoU= =vjIr -----END PGP SIGNATURE-----

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Denning and Clipper...
by pcw＠access.digex.net 17 Dec '03

17 Dec '03

>> One thing this shows, even if the application of the technique turns out >> to be too difficult to be practical, is that Dorothy Denning's evaluation >> of the design was worthless. That team should have found this themselves. >> No wonder she was trying to play it down in the NYT. > >It was my understanding that Denning was just looking at the Skipjack >algorithm, and not the clipper unit as a whole. I wouldn't be too quick >to condemn her on this point. Of course, Dorothy Denning could simply say, "Gosh, the Blaze result shows how to make Clipper _more_ secure for the average user. Now they don't have to worry about the government. I stand by my assessment that it is secure."

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Re: Faster way to deescrow Clipper
by sidney＠taurus.apple.com 17 Dec '03

17 Dec '03

Could someone please enlighten me on this: It seems from the descriptions of the hack to fake a LEAF that 1) When two Clipper chips are going to communicate, one of them generates the session key and sends a LEAF to the other chip, 2) The second chip recognizes the LEAF as being valid based on the validity of the checksum, but does not determine the session key from the LEAF. If that's the case, then 1) How does the second chip find out what the session key is? 2) Doesn't the second chip also have to generate and send a LEAF, if for no other reason than to identify itself to the wiretappers, and if so won't that give away the session key if that chip's device is not also hacked? 3) If all that is needed for this hack is a LEAF with a proper checksum, why go through the brute force method of generating random LEAFs? Why not just buy (or steal or whatever) another Clippered device that you never use for real communication so the wiretappers have no record of who has that serial number, and get LEAFs from it? For that matter, why can't you obtain one LEAF from listening to anybody's Clippered transmission and use it over and over again? It can't be *that* simple, can it? -- sidney <sidney(a)taurus.apple.com>

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Matt Blaze & Tessera Linked in NYT Again
by Duncan Frissell 17 Dec '03

17 Dec '03

Check the first page of the Bussiness Section of this morning's NYT for an article by John Markoff on Matt and Tessera. " 'The point is that the back door has a broken hinge,' said William Ferguson, vice president of Semaphore Corporation" DCF

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Re: HACK - U HAVE NO PRIVACY
by gtoal＠an-teallach.com 17 Dec '03

17 Dec '03

Please tell me you posted this as a joke and didn't even contemplate it for a microsecond! Haven't you ever heard of Craig Shergold? Say, you're not the same lefty who's listed in the alt.syntax.tactical FAQ are you? G

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Re: no subject (file transmission)
by gtoal＠an-teallach.com 17 Dec '03

17 Dec '03

See Tim May's "blacknet" spoof from last year. Anonymous mail pools have been the subject of long discussions. We were talking about it just last week actually - I pointed out that with suitable newsclip software you didn't even need a designated pool group. G PS I got thrown off the machine I was using to run the newsclip stuff on, so no more experiments with that for a long time...

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The Delhi Detweiler
by rishab＠dxm.ernet.in 17 Dec '03

17 Dec '03

gtoal(a)an-teallach.com (Graham Toal): > PPS While in paranoid mode, I thought I'd mention that I've noticed > some of Detweiler's mannerisms emanating from email in New Delhi of > all places. Weird. I think I must be cracking up. I've been worried myself, BBSes here have had a number of posts against those who oppose our Government's recent moves to be nasty to BBSes. The style of these posts is very Detweiler; maybe you can now get a degree in Detweilerese? Or did you mean me ;-) -------------------------------------------------------------------------- Rishab Aiyer Ghosh rishab(a)dxm.ernet.in Voicemail +91 11 3760335; Vox/Fax/Data 6853410 H-34C Saket New Delhi 110017 INDIA The National Fairness to Game Animals Association says: Support your right to arm bears! --------------------------------------------------------------------------

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IMP (was Re: ecash-info (
by Duncan Frissell 17 Dec '03

17 Dec '03

H > 2.) It seems to me that that e-cash, contrary to the status quo's H >thinking, H > is *critical* to internet commerce. H > H >No, it's not critical. Some form of transaction mechanism is H >critical. Privacy is not critical to the bulk of the economy, H >though. Face up to it. If it were, it would be so obvious that we H >wouldn't be discussing it on a mailing list. In fact, _we_ wouldn't be H >discussing it, but rather a whole bunch of bank vice presidents. The nicest thing about electronic money is not that anonymous digital cash is possible. but that the money is electronic. This means cheap transaction costs. This means that even if "banks" deploy ID-based rather than anonymous transaction systems, civilians can quickly step in and offer to broker anonymous transactions for those who prefer their privacy. Just as you can cash checks for other people today, you will be able to carry out transactions for others on the nets. Since it is much easier to operate these kinds of services in an electronic payment system with automation and on-line verification, suppliers should appear if the demand warrants. Since people will be in different physical locations and legal jurisdictions proof of wrong doing will be hard to come by. DCF "It is perfectly possible to overthrow the old order without picking up a gun or violating any (significant) law. If the conditions of human life change as radically and rapidly as they seem destined to, the (always bizarre) notion that groups of small oligarchies are competent to run the lives of everyone on earth will be swept aside almost accidentally as people move into their new lives." -- DCF --- WinQwk 2.0b#1165

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Re: Faster way to deescrow Clipper
by wcs＠anchor.ho.att.com 17 Dec '03

17 Dec '03

> > ...not be able to decrypt the communications, but they still get your ID. > >"your ID"? You mean your phone's ID. Goodness gracious, if you were > >a criminal, you wouldn't go out and steal someone else's Clipper > >phone, would you? Let's not get too high tech here, just because we > >have the ability. > > Or you could just steal someone else's LEAF, by keeping a copy of it, and use > that for spoofing. Then you could have a valid IV too... The IV is session-dependent, and both ends generate it. We don't know where in the LEAF the chipid is, but if they use a fixed format and don't do a key-dependent permutation of the LEAF bits, it shouldn't be hard to figure out (unless the checksum comes first and they use a block-chaining encryption, in which case you know you lose.) That would let you create rogue LEAFs with known users' chipids, which would be interesting - does anyone want to make 65536 calls to clipperphone(a)whitehouse.gov :-) ? (Yeah, it's not quite that simple.) (If you do need a lot of data, cellphones are a good source, since the cellphone operators' chipids are likely to be wellknown, though rapidly tapped.) Paranoid-speculation-mode: Of course, if you can forge LEAFs with their chipid, they can forge LEAFs with yours, which could be used to manufacture interesting evidence.... Bill

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