December 2003 - cypherpunks-legacy

Trapdoor vs. Escrow
by baldwin＠LAT.COM 17 Dec '03

17 Dec '03

I was shock when I read the material in John Gilmore's message of 12/30/93 (Revised Clipper FOIA results from Asst Secretary of Defense). It strongly suggests that the government has two options: 1. Key Escrow, and 2. Trapdoor chips. The comment about ATT being willing to make the chips suggests that the clipper/Capstone project includes BOTH Key Escrow and Trap Door. The chips would use a subliminal channel (like the bits that can be hidden in a DSS signature) to reveal the chips key. Presumably the revealed key is encrypted to make sure that only the "good guys" can recover the key. Notice that the NSA has plenty of motivation to have already developed trapdoor chips long before the need to use them in public cryptography. The US exports its crypto hardware to "friendly nations" and has a strong interest in being able to read our friend's traffic. The old fashion way of doing this was to sell old crypto hardware to these nations even though the NSA new how to break the systems. I recall that an NSA employee went to jail for telling Sweden that the NSA knew how to break the Hagelin cipher machine at the end of WWII when the US gave Sweden and other nations a large number of these machines. Given the length of the jail sentence (30 years), I suspect that he did other crimes, but the government did not want to expose them. Perhaps the modern way of reading our friends traffic is to sell them chips that reveal key bits via a subliminal channel. --Bob Baldwin

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Re: GPS and security
by jerry＠terminus.dell.com 17 Dec '03

17 Dec '03

In article <2fq4rk$t78(a)uudell.us.dell.com> you write: >From: m5(a)vail.tivoli.com (Mike McNally) >Subject: GPS and security > > >CBS's "60 Minutes" had a "Oooh Scarey" segment about the Global >Positioning System last Sunday. The scarey part is, according to 60 >Minutes, that any old terrorist government can now put together >accurate guided missles and wreak death and destruction upon our >homeland. The crux of the problem is that the system broadcasts out >positioning information to one and all indiscriminately, and according >to the show there's no way we can stop it. A couple of points here. Any terrorist group can get pin-point accuracy with a suitcase bomb. Someone could have launched an ICBM at the world trade center, but it was much cheaper to just rent a truck. Terriorist don't need high-tech. GPS has two modes, civilian and military modes. When the GPS is operating in "secure" mode civilian access gives 10meter accuracy. The military codes give accuarcy down to ~1meter. The GPS broadcasts using a spread spectrum mode and the encoding is based on the frequency hopping. Now if a military unit wanted to blow up your tank, they would need the 1meter accuarcy. During desert storm, the u.s. military turned off the secure mode, because all of the equipment they had use the civilian mode. >Because my mind is regularly exposed to wild conspiracy theories and ... >they could be told to do several things in case of national emergency: > >* Shut down (probably possible; they may have actually mentioned >this on the show). Problem is that lots of friendlies may grow to >rely on the data for life-critical things, like guiding commercial >airliners. All of the systems I know of, including airplanes and ocean going ships has LORAN C, GPS and inertial nagivation systems. Currently there are still holes in GPS coverage, to get a "good" fix, you need three satilites overhead. Currently there are still gaps where only two satilites are available. >* Shut down normal transmission and begin strongly encrypted >transmission. No mention of this; apparently, the satellites were >originally designed with some sort of weak system that made the data >difficult to use for high-accuracy purposes, but that's been defeated >(by the FAA or someone contracted thereto). Actually the system was designed to offer the two modes, but advances in technology have allowed the GPS reciever people to take into account things like relativity(high speed satilites, freq shifts etc.), using more than 3 satilites to get a better fix, averaging techniques etc. With some more complex equipment and a "known" reference you can use GPS to measure down to centimeter accuarcy. Not at very high speeds though... >I don't know much about how this system works, so I don't know whether >any of my thoughts are relevant. It's probably most likely that the >government indeed blasted these things up into space without >considering using encryption technology to enhance security. Actually the government put a lot of thought into the security, but seeing as the actual data is just timecode pulses, its not real easy to secure, but with a good encryption and a frequency hopping setup like GPS, you can do a lot. I think that there are provisions for disabling the civilian channel altogether during wartime. It would be interesting to see what happens to MCI, Sprint, etc that use GPS to syncronize they're high speed syncronis optical networks... The should work fine for several hours but after a couple of days, the phase a frequency errors in the timecode equipment would lead to a high error rate. MCI and sprint may also use LORAN C for backup, I don't remember. -- | Jeremy Porter ----------------- Dell Computer Corp. ---- | Systems Engineering --- jerry(a)terminus.us.dell.com -------- |------------------------------------------------------------- | Support your Second Amendment rights to encryption technology.

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Here we go again ...
by Bradley W. Dolan 17 Dec '03

17 Dec '03

I am one of those evil troglodyte NRA members mama Janet warned about. Along with my ignorant red-necked bretheren, I have protested increasing encroachment on my right to keep and bear arms. The standard pattern of the encroachment has been for our philosopher-kings to publicize incidents wherein something bad occurred involving a firearm, followed up by rules infringing upon our rights in the name of public safety. Lately the philosopher-kings have discovered the internet. Today, the FBI has announced that an evil bomber may be using it. I fully expect to hear soon that bad people may be using crypto on the net for nefarious purposes, and that crypto should be outlawed. It's deja vu all over again. bdolan(a)well.sf.ca.us ask for PGP data

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Re: Trapdoor vs. Escrow
by Hal 17 Dec '03

17 Dec '03

I think the term "trapdoor" in this context merely refers to known characteristics of the Clipper chip and does not imply any additional abilities to decrypt messages other than what has been revealed. A "trapdoor" is generally some secret which allows you to decrypt messages which could not be decrypted without the secret. It is normally applied in the context of one-way functions but I suppose an encryption system could be thought of as one-way. In this case I think the trapdoor may just refer to the Law Enforcement field which, upon decryption, allows information to be recovered so that the message can be read without the user's cooperation. The comment about the trapdoor issue being independent of the escrow issue harked back to Denning's original suggestion, which was that all users of encryption would have to escrow their keys with the government. This could be done in the context of any cryptosystem, such as DES or RSA. The trapdoor makes the system more convenient for users, hence perhaps more acceptable. But the escrow provision is the aspect that the government really cares about. BTW, there were some comments on sci.crypt about how this review document showed that the government was not as opposed to our views as had been thought. On the contrary, my take was that this document reflected something of a maverick view, one which was not politically acceptable with those in authority. Note the critical comments about the document containing unsupported assertions, a common buzzword for "views I don't agree with." I don't think the author of this review has helped his career. Hal Finney hfinney(a)shell.portal.com

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"Almost 2001" -- NBC transcripts available via Gopher
by Anonymous 17 Dec '03

17 Dec '03

forwarded message - From: kadie(a)eff.org (Carl M. Kadie) Newsgroups: comp.org.eff.talk Subject: NBC transcripts Date: 30 Dec 1993 19:29:20 -0500 Organization: Electronic Frontier Foundation To see transcripts of "Almost 2001: an NBC [News] series on the communications revolution", try: gopher -p1/Communications/2001 gopher.well.sf.ca.us 70 - Carl -- Carl Kadie -- I do not represent EFF; this is just me. =kadie(a)eff.org, kadie(a)cs.uiuc.edu =

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End of Year E-Zine Listing
by Anonymous 17 Dec '03

17 Dec '03

Once again, we find ourselves facing a new jahre and pondering the untold wonders of the anarchy of cyberspace! In celebration of this joyous occasion, I've decided to post a compilation of electronic 'zines for your perusal. I especially like the reference for Practical Anarchy and will probably send a copy of this message to our old chum, Larry "the squid" Detweiler. Enjoy, - Spooge /---------------- good stuff follows ------------------/ Last updated: 27-Aug-93 by John Labovitz <johnl(a)netcom.com> This is a summary of electronically-accessible zines. The format should be fairly self-explanatory. In most cases, descriptions are excerpted from the masthead of the zine listed. [For those of you not acquainted with the zine world, "zine" is short for either "fanzine" or "magazine," depending on your point of view. Zines are generally produced by one person or a small group of people, done mostly for fun, and often irreverent, bizarre, and/or esoteric. Zines are not "mainstream" publications -- they generally do not contain advertisements (except, sometimes, advertisements for other zines), do not have a large subscriber base, and are not produced to make money.] If you have any additions, deletions, or changes to this list, please email them to johnl(a)netcom.com. I will post this list (and/or changes to the list) to various mailing lists and Usenet news groups. It can also be obtained via anonymous FTP from netcom.com as "/pub/johnl/zines/e-zine-list", and via email (either single issues or subscriptions) from e-zines-request(a)netcom.com. If you publish an e-zine, or know someone who does, please send a copy to e-zines(a)netcom.com and I'll add the relevant info to this database. All comments, suggestions, changes, deletions, etc., are welcomed and encouraged. John Labovitz johnl(a)netcom.com ----- Arm The Spirit "Arm The Spirit is a anti-imperialist/autonomist collective that disseminates information about liberation struggles in advanced capitalist countries and in the so-called 'Third World.' Our focus is on armed struggle and other forms of militant resistance but we do not limit ourselves to this. In Arm The Spirit you can find news on political prisoners in North America and Europe, information on the struggles of Indigenous peoples in the Americas, communiques from guerrilla groups, debate and discussion on armed struggle and much more. We also attempt to cover anti-colonial national liberation struggles in Kurdistan, Puerto Rico, Euskadi and elsewhere." Editor(s): Autonome Forum <aforum(a)moose.uvm.edu> Format: ASCII text FTP: etext.archive.umich.edu:/pub/Politics/Arm.the.Spirit E-Mail: aforum(a)moose.uvm.edu, subject: "ATS: e-mail request" Postal: Arm The Spirit, c/o Wild Seed Press, POB 57584, Jackson Stn., Hamilton, Ontario, L8P 4X3, Canada Arm The Spirit, c/o Autonome Forum, POB 1242, Burlington, VT 05402-1242, USA Phone: +1 416 527 2419 (FAX for Canadian group) Armadillo Culture "Being the excremeditation of a hyperactive armadillo's activities, opinions, and other stuff..." Editor(s): Steve Okay <sokay(a)mitre.org> Format: ASCII text FTP: etext.archive.umich.edu:/pub/Zines/Armadillo.Culture Postal: Armadillo Culture, 2857 Foxmill Rd. Herndon, VA 22071, USA ART COM "An online magazine forum dedicated to the interface of contemporary art and new communication technologies." Editor(s): Carl Eugene Loeffler <artcomtv(a)well.sf.ca.us> Format: ASCII text Usenet: alt.artcom Postal: ART COM, POB 193123 Rincon, San Francisco, CA 94119-3123, USA Phone: +1 415 431 7524 (voice), +1 415 431 7841 (fax) Other: Whole Earth 'Lectronic Link (WELL): ART COM Electronic Network (ACEN) BLINK "BLINK would like to be a forum for the issues surrounding the intersection of consciousness and technology. This is our best defense against postmodern angst: To critically look at and anticipate the cultural and social changes spurred by the rapid development of technology." Editor(s): Justin Kerr <ratsbats(a)casbah.acns.nwu.edu> Joe Germuska (managing editor) Danny Dunlavy (chiphead) Jake Eldridge (assistant editor) Format: ASCII text FTP: blink.acns.nwu.edu:/pub/blink Gopher: gopher.well.sf.ca.us Computer Underground Digest "An open forum dedicated to sharing information among computerists and to the presentation and debate of diverse views." Editor(s): Jim Thomas and Gordon Meyer <TK0JUT2(a)NIU.BITNET> Format: ASCII text FTP: ftp.eff.org:/pub/cud etext.archive.umich.edu:/pub/CuD/cud halcyon.com:/pub/mirror/cud aql.gatech.edu;/pub/eff/cud ftp.ee.mu.oz.au:/pub/text/CuD (Australia) nic.funet.fi:pub/doc/cud (Finland) ftp.warwick.ac.uk:pub/cud (United Kingdom) Gopher: etext.archive.umich.edu Postal: Jim Thomas, Department of Sociology, NIU, DeKalb, IL 60115, USA Phone: +1 815 753 0303 (voice), +1 815 753 6302 (fax) Usenet: comp.society.cu-digest CompuServe: DL0 and DL4 of the IBMBBS SIG; DL1 of LAWSIG; DL1 of TELECOM Other: GEnie: PF*NPC RT libraries; VIRUS/SECURITY library America Online: PC Telecom forum under "computing newsletters" Delphi: General Discussion database of the Internet SIG PC-EXEC BBS (+1 414 789 4210) Rune Stone BBS (IIRG WHQ) (+1 203 832 8441) NUP:Conspiracy RIPCO BBS (+1 312 528 5020) via Fidonet File Request from 1:11/70 ComNet in LUXEMBOURG BBS (+352 466893) Bits against the Empire BBS (+39 461 980493) (Italy) Crash "A guide to traveling through the underground. Alternative travel stories, hints, and tips." Editor(s): John Labovitz <johnl(a)netcom.com> Miles Poindexter Nigel French Format: ASCII text FTP: netcom.com:/pub/johnl/zines/crash Postal: Crash, 519 Castro #7, San Francisco, CA 94114, USA CTHEORY -- Virtual Review of Books for Post-Modem Theory "CTHEORY is a new international, electronic review of books on theory, technology and culture. Reviews are posted monthly of key books in contemporary discourse as well as theorisations of major 'event-scenes' in the mediascape. Editors and contributors include: Kathy Acker, Jean Baudrillard, Bruce Sterling, Arthur and Marilouise Kroker, Deena and Michael Weinstein. CTHEORY will also offer the possibility of interactive discussions among its subscribers in the electronic theory 'sim-posium/salon.'" Editor(s): <ed22(a)musica.mcgill> Format: ASCII text E-Mail: LISTSERV(a)VM1.MCGILL.CA with text body: "SUBSCRIBE CTHEORY <full-name>" Cyberspace Vanguard "News and Views of the Science Fiction and Fantasy Universe" Editor(s): TJ Goldstein <tlg4(a)po.cwru.edu> Sarah Alexander, Administrator <aa746(a)po.cwru.edu> Format: ASCII text E-Mail: cn577(a)cleveland.freenet.edu Cyberspace Vanguard@1:157/564 (FidoNet) CVANGUARD (Delphi) Postal: Cyberspace Vanguard, POB 25704, Garfield Heights, OH 44125, USA Drum "Drum is not an isolated event but an ongoing process." Editor(s): R. Patrick Jones <dh644(a)cleveland.Freenet.Edu> Format: ASCII text FTP: etext.archive.umich.edu:/pub/Zines/Drum Gopher: gopher.well.sf.ca.us Ego Project "This 'zine is a product of me and as such will contain anything I feel like putting in it. Whatever I feel like putting in it shall include, but is not limited too, anything I feel applies to Gothdom in general. Album/single/tape reviews, book and movies reviews, etc. The Sisters of Mercy and the Mission are my main focuses, but since neither of them put out music on anything resembling a frequent basis I imagine other groups will be featured quite frequently." Editor(s): Corey Nelson <ieya(a)byron.u.washington.edu> Format: ASCII text Gopher: gopher.well.sf.ca.us Postal: Ego Project, 1717 Monroe #b, Bellingham, WA 98225, USA Factsheet Five / Factsheet Five - Electric "FactSheet Five is the central clearinghouse of information about zines, those opinionated publications with press runs of 50 to 5000 (often done through surrepticious use of on-the-job supplies and xerox). Mike Gunderloy of Rennsalaer, NY published 44 editions of F5. Hudson Luce published the final issue, #45. I opened my big mouth (or, rather, let my fingers blab away) about doing an online, net-accessible version of FactSheet Five." Editor(s): Jerod Pore <jerod23(a)well.sf.ca.us> (electronic version) Seth Friedman <sethf5(a)well.sf.ca.us> (paper version) Format: ASCII text FTP: etext.archive.umich.edu:/pub/Factsheet.Five nigel.msen.com:/pub/newsletters/F5-E src.doc.ic.ac.uk:/literary/newsletters/factsheet-five Gopher: gopher.well.sf.ca.us WAIS: nigel.msen.com Postal: Factsheet Five, 1800 Market St., San Francisco, CA 94102, USA (This is for *BOTH* the electronic and paper versions; or for items that can't be delivered to a PO box) Seth Friedman, POB 170099, San Francisco, CA 94117-0099, USA (This is for the paper version *only*, especially subscriptions) Other: The WELL BBSes around the world FUNHOUSE! -- The cyberzine of degenerate pop culture "Dedicated to whatever happens to be on my mind at the time I'm writing. The focus will tend to be on those aspects of our fun-filled world which aren't given the attention of the bland traditional media, or which have been woefully misinterpreted or misdiagnosed by the same. FUNHOUSE! is basically a happy place, and thus the only real criteria I will try to meet is to refrain from rants, personal attacks, and flames -- and thus FUNHOUSE! is an apolitical place. Offbeat films, music, literature, and experiences are largely covered, with the one stipulation that articles are attempted to be detailed and well documemnted, although this is no guarantee of completeness or correctness, so that the interested reader may further pursue something which may spark her interest." Editor(s): Jeff Dove <jeffdove(a)well.sf.ca.us> Format: ASCII text FTP: netcom.com in /pub/johnl/zines/funhouse High Weirdness by Email random Internet information Editor(s): <mporter(a)nyx.cs.du.edu> Format: ASCII text Gopher: gopher.well.sf.ca.us International TeleTimes "International Teletimes is a general interest magazine. There are several recurring monthly columns but the rest of the content changes from month to month as new themes are chosen. The goal of Teletimes is to attract a large variety of writers from all over the world so that the readers will be exposed to a great variety of ideas and opinions." Editor(s): Ian Wojtowicz <ian(a)breez.wimsey.com> Format: Macintosh Doc-Maker application FTP: sumex-aim.stanford.edu:/info-mac/per/teletimes-*.hqx Postal: TeleTimes International, 3938 West 30th Ave., Vancouver, BC V6S 1X3, Canada Other: OneNet (network of FirstClass BBSes) InterText "InterText is a bi-monthly fiction magazine with over 1000 subscribers worldwide." Editor(s): Jason Snell <intertxt(a)network.ucsd.edu> Geoff Duncan <gaduncan(a)halcyon.com> Format: ASCII text PostScript FTP: etext.archive.umich.edu:/pub/EFF.journals/InterText CompuServe: Electronic Frontier Foundation's "Zines from the Net" section, accessible by typing "GO EFFSIG" Obscure Electronic "OBSCURE is the zine that profiles the people in this publishing subculture." Editor(s): James P Romenesko <intertxt(a)network.ucsd.edu> Format: ASCII text FTP: etext.archive.umich.edu:/pub/Zines/Obscure.Electric Gopher: gopher.well.sf.ca.us Postal: POB 1334, Milwaukee, WI 53201, USA People Power Update The newsletter of the bicycle advocacy group "People Power" Editor(s): Ron Goodman <goodman(a)cats.ucsc.edu> Format: ASCII text FTP: netcom.com:/pub/johnl/zines/ppu Postal: People Power, 226 Jeter Street, Santa Cruz, CA 95060, USA Phone: +1 408 425 8851 (voice/fax) Play by EMail "Electronic 'zine about free play-by-electronic-mail wargames. Reviews, game openings, information." Editor(s): Greg Lindahl <gl8f(a)fermi.clas.Virginia.EDU> Format: ASCII text FTP: ftp.erg.sri.com:/pub/pbm/PBEM-Fanzine Gopher: gopher.well.sf.ca.us Usenet: rec.games.pbm Practical Anarchy Online "An electronic zine concerning anarchy from a practical point of view, to help you put some anarchy in your everyday life. The anarchy scene is covered through reviews and reports from people in the living anarchy." Editor(s): Chuck Munson <cmunson(a)macc.wisc.edu> Bitnet: cmunson(a)wiscmacc.bitnet Mikael Cardell <cardell(a)lysator.liu.se, Fidonet: Mikael Cardell@2:205/223 Format: ASCII text Gopher: gopher.well.sf.ca.us Postal: Practical Anarchy, POB 173, Madison, WI 53701-0173, USA Practical Anarchy, c/o Mikael Cardell, Gustav Adolfsgatan 3, S-582 20 Linkoping, Sweden Quanta "Quanta is the electronically produced and distributed magazine of science fiction and fantasy. As such, each issues is packed with fiction from amateur and professional authors from around the world and across the net." Editor(s): Daniel K. Appelquist <quanta(a)andrew.cmu.edu> Format: PostScript ASCII text FTP: export.acs.cmu.edu:/pub/quanta ftp.eff.org:/journals/Quanta lth.se:/documents/Quanta catless.newcastle.ac.uk:/pub/Quanta Gopher: gopher-srv.acs.cmu.edu (in the Archives directory) Postal: Quanta, 3003 Van Ness St. NW #S919, Washington, DC 20008, USA CompuServe: "Zines from the Net" area of the EFF forum (accessed by typing GO EFFSIG) Scream Baby "What do I want? Besides world peace, a sexy Mexican maid, and someone to use their fucking brains around here, I want a really good all-encompassing-sub-culture zine. Music, literature, art, television, film, weird space-time kinks, events, information, news, humor, interviews, and re:views of 'Stuff I Think Is Cool.' Not all at once, of course. Each issue of Scream Baby will come out whenever I can scrape together 25-30 kilobytes of really good stuff." Editor(s): Blade X <bladex@bladex@wixer.cactus.org> Format: ASCII text FTP: etext.archive.umich.edu:/pub/Zines/ScreamBaby ftp.eff.org:/pub/journals/ScreamBaby Postal: Cyberlicious <tm>, POB 4510, Austin, TX 78765 USA Other: WWIV: 46@5285 Unplastic News "the odd e-mail magazine w/a fever" Editor(s): <tibbetts(a)hsi.hsi.com> Format: ASCII text FTP: ftp.eff.org:/pub/cud/misc/journals etext.archive.umich.edu:/pub/EFF.journals/Unplastic_News quartz.rutgers.edu:pub/journals Gopher: gopher.well.sf.ca.us Voices from the Net "There are a lot of folks with at least one foot in this complex region we call (much too simply) "the net." There are a lot of voices on these wires. From IRC to listservs, MUDspace to e-mail, Usenet group to commercial bbs -- all kinds of voices -- loud and quiet, anonymous and well-known. And yet, it's far from clear what it might mean to be a "voice" from, or on, the net. Enter "Voices from the Net": one attempt to sample, explore, the possibilities (or perils) of net.voices. Worrying away at the question. Running down the meme. Looking/listening, and reporting back to you." Editor(s): Bookish <tibbetts(a)hsi.hsi.com> CountZer0 <mgardbe(a)andy.bgsu.edu> NEURO <fbohann(a)andy.bgsu.edu> Format: Macintosh HyperCard stack ASCII text FTP: sumex-aim.stanford.edu:/info-mac/per/voices-*.hqx etext.archive.umich.edu:pub/zines/Voices E-Mail: Voices-request(a)andy.bgsu.edu to subscribe: subject: Voices from the Net body: subscribe Whole Earth Review "We are dedicated to demystification, to self-teaching, and to encouraging people to think for themselves. Thus our motto: 'ACCESS TO TOOLS AND IDEAS.' Tools in the Whole Earth sense include hammers, books, and computer conferencing systems. Our readers are a community of tool-users who share information with one another. The ideas we make accessible have not often been found in university courses, but are becoming recognized as part of what you need to know to be truly educated. Our readers contribute to the editorial content as well, with both reviews and articles." Editor(s): <> Format: ASCII text Macintosh PageMaker 4.2 files Gopher: gopher.well.sf.ca.us E-Mail: wer(a)well.sf.ca.us Postal: Whole Earth Review, 27 Gate Five Road, Sausalito, CA 94965, USA Phone: +1 415 332 1716 (voice), +1 415 332 3110 (fax) ----- Sites archiving e-zines with FTP: ftp.eff.org etext.archive.umich.edu ftp.cic.net quartz.rutgers.edu ftp.msen.com ftp.halcyon.com world.std.com netcom.com in /pub/johnl/zines) nigel.msen.com in /pub/newsletters grind.isca.uiowa.edu (128.255.19.233) in /info/journals Sites archive e-zines with Gopher: gopher.eff.org etext.archive.umich.edu gopher.cic.net gopher.msen.com gopher.well.sf.ca.us world.std.com gopher.unt.edu -----

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Benford revisited:
by jpinson＠fcdarwin.org.ec 17 Dec '03

17 Dec '03

In regards to my posting about the New Scientist article on "Benford's" law (unexpected number ratios in observed data), I received many comments along the line of: > I suggest you look at any slide-rule or log graph paper for the > simple explanation of this trivial phenomenon. Actually, the New Scientist article gave a very clear explanation of Benford's law, and how it can be a simple artifact of the way numbers are counted. The article caught my attention, when it went on to explain how other phenomena, such as alpha particle half-lifes can follow Benford's law for completely different reasons. I won't attempt to retype the entire article, but Buck, Merchant, and Perez, reported in the European Journal of Physics (Vol 14, p59) that both expected and observed half-lives followed Benford's law. Quoting New Scientist: "..Why should nature operate in this curious manner? Buck and his colleagues point out that in the case of alpha decay, there may be a good physical reason. In 1928 George Gamow used the newfangled theory of quantum mechanics to describe alpha decay. The alpha particle lives inside a "potential well" in which the energy is lower than in an any other state that it can normally reach. It escapes by "tunneling" through the potential well. The probability of tunneling occurring within a given time is found by forming a so- called "tunneling integral" and raising it to a power that is proportional to time. So tunneling times, and hence half-lives naturally correspond to a geometric series, not a arithmetic one. If nature chooses the tunneling integral "randomly" with uniform probability, then the power-law dependence of alpha-particle half-lives on this integral leads to scale-invariant behavior, and so to Benford's law. " I am not a physicist or a mathematician, so I can't speculate on the validity of these statements. However, all this did make me wonder if advances in fractal geometry, or chaos theory, might one day reveal patterns in seemingly random numbers derived from real word phenomena. Since most random numbers used in cryptography are derived from real word phenomena, we should be aware of such potential influences. Actually, we don't have to bring in fractals, chaos, or Benford's law to have reason for concern about using real world based random numbers. A method commonly recommended on this list for generating random numbers is to take the audio input from a workstation (with no mike attached) and then compress the output: cat /dev/audio | compress - >random-bits-file First of all, without extensive study of the audio output (from the *specific* source) who can say the output is random in the first place? Harmonics from the various electrical circuits in the computer could easily produce non-random effects (like a 60 cycle hum). The second aspect that concerns me is the use of compression. Unless you are very familiar with the type of data compression being used, how can you be sure there aren't various signatures, tables, data structures, or headers being inserted into the output. Indeed, I had to go no further that the beginning of a data file produced by the "Compress" program, to find nonrandom numbers. All such files begin with the same three bytes! If something so obvious is being overlooked, what about more subtle patterns? Anyway, it seems to me there can be many factors "contaminating" random numbers based on physical phenomena, factors ranging from a simple 60 cycle hum to unrecognized fractal patterns. It is perhaps a good idea to routinely "massage" random numbers to remove both recognized and unrecognized contamination. Xor'ing random numbers derived from two or more different sources might be sufficient. If done properly, such a procedure may produce non-Benford, evenly-distributed random numbers, which might be considered superior to the original. Actually, I tend to be rather cautious about such things and am always on the lookout for possible "contamination". I also try to keep an open mind to new ideas. Jim Pinson

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Re: GPS and security
by Brenden Kootsey 17 Dec '03

17 Dec '03

Like Mike, I don't claim to know much about the GPS, and I didn't see the 60 Minutes report, but it was my understanding that at least a portion of the signal is encrypted. The signal available to us mortal (non-U.S. military) types has a built-in inaccuracy; while it is still accurate enough for some general use, it is not nearly as accurate as the signal available to the military. Anyone have more of the technical details, especially regarding the accuracy?

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anonymous "video on demand"
by jim＠bilbo.suite.com 17 Dec '03

17 Dec '03

Does anyone know of a good, practical way of doing "video on demand" in such a way that the video supplier can't track the videos you select? I suppose the trivial solution would be to send your video selection request (and service fee) through a "anonymous video remailer". The video supplier would send the encrypted video back to you via the remailer. Since I don't see "anonymous video remailers" as being a practical solution in the near future, I'm more interested in finding out if there are other ways of solving this problem. This sounds like an All-Or-Nothing Disclosure Of Secrets problem. However, all I know about ANDOS is what I read in "Applied Cryptography", and the algorithm it describes doesn't seem a good fit. Are there other ANDOS algorithms that may work better? Jim_Miller(a)suite.com

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Anonymous Video on Demand
by Mike Ingle 17 Dec '03

17 Dec '03

>Does anyone know of a good, practical way of doing "video on demand" in >such a way that the video supplier can't track the videos you select? Are you thinking of physical videotape or electronic distribution? For electronic distribution, suppose you have a fiber-optic cable with n channels, where n is a large number. You send in your request and pay with digicash or a prepaid system like a prepaid phone card. You send them an encryption key, and they broadcast the movie over one of the channels. Or they generate the encryption key and send it to you using a key you gave them. Problem: you can share the encryption key with a few thousand of your closest friends, thus cheating the video dealer. They could require you to make a digicash deposit, and offer a reward for anyone who reports a pirated encryption key. If you give out the key, someone reports it and gets half your deposit, and they keep the rest. But a group of people who all trust each other could still rip off the video dealer. You could have a decoder with a key unknown to you, but that system would be only as strong as the physical security of the decoder. Is there any way to use offline-digicash-like techniques to set up a system so that if you reveal the encryption key, you also reveal your identity? This would be a real deterrent. For a videotape system, there is no strong way I can think of to prevent revealing your identity. You have to pick up the tape, and they have to know what to record on it or which tape to put out. A camera at the site could always catch you in the act of retrieving the tape. It is possible to protect the dealer in an anonymous transaction, but not the customer. The dealer, if he was selling pirate tapes, could go out and hide them in various places. In exchange for your digicash, he tells you where one is. --- Mike

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