Re: who goes 1st problem
On Tue, May 11, 2004 at 09:10:35PM +, Jason Holt wrote: [...] issue [...] would be how you actually get your certs to the other guy. Hidden credentials, as Ninghui pointed out, assume you have some means for creating the other guy's cert, [...] The OSBE paper, OTOH, assumes we're going to exchange our certificates, just without the CA signatures. Then I can send you messages you can only read if you really do have a signature on that cert. I think this is ok. Would suggest you remove the nym field, have one-use credentials (to avoid linkability across provers), and only reveal separate nym cert after have satisfied policy. But I've always thought that was problematic, since why would honest people bother to connect then use fake certs? Again ok. You send either fake cert, or real cert for as many attributes as the CA issues. You may not even know what some of the attributes that the CA issues are, all you know is the number of them. You use and / or connectives between them (using k xor r, k; or r, r respectively) but using OBSE algorithm (xor refers to improved HC scheme by HC authors in http://eprint.iacr.org/2004/109/). The attacker doesn't need to see the signature - he believes you. So honest users would need to regularly give out fake certs so they can hide their legit behavior among the fake connects. Yes, that works, but is defined required part of protocol; that way optimal cover (within limits of partial policy concealment) is given for sensitive attributes, policies etc. But maybe Robert's improved secret sharing scheme from the new HC paper can give us some ideas: 1. Alice sends blinded signatures for each of her relevant certs, not revealing which signature goes with each cert, and not revealing the cert contents. Sounds same as above. 2. Bob generates the contents of each of Alice's certs relevant to his policy, and simply generates each possible combination of hash-of-cert-contents and blinded-signature. One from each row will be a match-up between contents and signature, and Alice will have to figure out which. Unfortunately, this requires n^2 multiplies and exponentiations. That's true. Think there is a trade-off between degree of concealment, and amount of permutations prover has to try. You could perhaps define an ordering of attributes safely, followed by dealing with unordered undeclared attributes. Other thought perhaps a FPGA like layout where all possible connectives patterns are represented, might allow to specify arbitrary boolean formulae with and / or connectives with full policy concealment but less space and time efficient. (Calling it prover is kind of odd I find when the prover convinces only himselfhe satisfies policy by default and optionally chooses whether to disclose that to verifier. And the prover is the passive entity receiving encrypted comms, which is back-to-front to usual prover-verifier comms pattern. Maybe sender and recipient is better.) Adam
We're jamming, we're jamming, we hope you like jammin too
At 03:09 PM 5/11/04 +0200, Eugen Leitl wrote: The second covers a hacking the system concept. I'd considered something similar myself, though different in approach. Rather than finding RFID chips and redistributing them, why not create programmable RFID broadcasters which could spoof other chips, and distribute these. The idea being to pollute any RFID detectors with a vast spew of superfluous data. RFID jamming should be very easy and a quite amusing DoS attack on commercial targets. Easy because its not frequency hopping, low power, and relatively low frequency. Particularly cute would be transmitting sex-toy codes intermittently. ASK any Elmer you happen to see, what's the best jamming, RFID.. (With apologies to the tuna industry and those too young to know the jingle. Or to know the RF double meanings.)
Prometheus Award finalists announced
For immediate release: May 12, 2004 Libertarian Futurist Society announces Prometheus Award finalists, and Hall of Fame finalists. The Libertarian Futurist Society has chosen finalists for its annual Prometheus Award for Best Novel and its annual Prometheus Hall of Fame for Classic Fiction. The winners will be announced at the 62nd World Science Fiction Convention, Noreascon Four in Boston, Massachusetts, September 26, 2004. 2004 Prometheus award finalists for Best Novel: (for novels published in 2003) (alphabetized by author) Naked Empire, by Terry Goodkind (Tor Books) The Pixel Eye, by Paul Levinson (TOR Books) Spin State, by Chris Moriarty. (Bantam Books) Harry Potter and the Order of the Phoenix" by J.K. Rowling (Scholastic Press) Sims, by F. Paul Wilson ( Forge Books) Hall of Fame finalist 2003-2004 award year It Can't Happen Here, a novel by Sinclair Lewis Lord of the Rings trilogy, novels by J.R. Tolkien The Weapon Shops of Isher, a novel by A. E. Van Vogt The Ungoverned, a short story by Vernor Vinge The Book of Merlyn, a novel by T.H.White Fourteen novels were nominated for this year's Prometheus Award for Best Novel. The other nominees were: The Anguished Dawn, a novel by James Hogan (Baen Books) State of Disobedience, a novel by Tom Kratman (Baen Books) Crossfire, a novel by Nancy Kress (Tor Books) Hecate's Glory, a novel by Karen Michalson (Tor Books) Quicksilver, a novel by Neal Stephenson (Harper Collins) Ruled Brittania, a novel by Harry Turtledove (Roc/NAL/Penguin) Red Thunder, a novel by John Varley (Ace Books) Gateways, a novel by F. Paul Wilson (Forge) The Holy Land, a novel by Robert Zubrin (Polaris Books) About two dozen works were nominated for this years' Hall of Fame award, including novels, short stories, film and TV. Both awards honor outstanding science fiction/fantasy that explores the possibilities of a free future, champions human rights (including personal and economic liberty), dramatizes the perennial conflict between individuals and coercive governments, or critiques the tragic consequences of abuse of power--especially by the State. The Prometheus Award, sponsored by the Libertarian Futurist Society (LFS), was established in 1979, making it one of the most enduring awards after the Nebula and Hugo awards, and one of the oldest fan-based awards currently in sf. Presented annually since 1982 at the World Science Fiction Convention, the Prometheus Awards include a one once gold coin and plaque for the winners. For more information, including a history of the award winners, visit the LFS website at www.lfs.org or contact LFS Director Victoria Varga ([EMAIL PROTECTED]), Best Novel Awards Committee Chair Michael Grossberg ([EMAIL PROTECTED]), or LFS President and Publicity Chair Chris Hibbert (650-968-6319, [EMAIL PROTECTED]) For a list of past winners please visit our website at: http://www.lfs.org/awards.htm -30-
Re: SASSER Worm Dude
On Mon, May 10, 2004 at 02:31:18PM -0400, Tyler Durden wrote: So a HS kid, living with his parents, is able to write a worm that takes out millions and millions of computers throughout the world running the latest MS OS. Uhshouldn't we arrest Bill Gates first? The decision is rational, because people are irrational, ignorant, and hence populistic gestures have a large payoff (and some deterrence to boot). Establishing liability for generic software is unprecedented, will take huge resources, time, and has low probability to succeed. So let's lock up the kid, and his buds. The professionals will thank you, too, for it keeps them out of the limelight due to the distraction, and increases the vulnerability exploitability shelf life. -- Eugen* Leitl a href=http://leitl.org;leitl/a __ ICBM: 48.07078, 11.61144http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net pgp0.pgp Description: PGP signature
Re: CDR: We're jamming, we're jamming, we hope you like jammin too
On May 12, 2004, at 12:47 PM, Major Variola (ret) wrote: At 03:09 PM 5/11/04 +0200, Eugen Leitl wrote: The second covers a hacking the system concept. I'd considered something similar myself, though different in approach. Rather than finding RFID chips and redistributing them, why not create programmable RFID broadcasters which could spoof other chips, and distribute these. The idea being to pollute any RFID detectors with a vast spew of superfluous data. RFID jamming should be very easy and a quite amusing DoS attack on commercial targets. Easy because its not frequency hopping, low power, and relatively low frequency. Particularly cute would be transmitting sex-toy codes intermittently. ASK any Elmer you happen to see, what's the best jamming, RFID.. (With apologies to the tuna industry and those too young to know the jingle. Or to know the RF double meanings.) I remember the tune (grin). Ah, childhood. Would RFID jamming really be effective? RFID scanners work when the chip passes the scanner - when a pallet passes a door for instance - at which point the scanner 'knows' that chips Abe, Bill, Charlie passed point Delta. To get the jammer to work it would have to be run past the scanner - I don't see how an RFID jammer planted in (say) the changing room at Wal-Mart would be an effective DoS? It's possible I'm ill-informed or just unclear on the concept. ~~brian
RE: We're jamming, we're jamming, we hope you like jammin too
You might want to look at the work RSA Labs is doing on 'blocker tags'. These are special tags which leverage the mechanism used to disambiguate the presence of multiple tags to make it look as if you are carrying 2^n (n usually 128) different tags at once. They propose a protocol to make them only block tags for items which have undergone sale to their final owner, but the idea could be applied to all tags. http://www.rsasecurity.com/rsalabs/rfid/index.asp Peter Trei Full Disclosure: I work for RSA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Major Variola (ret) Sent: Wednesday, May 12, 2004 1:48 PM To: [EMAIL PROTECTED] Subject: We're jamming, we're jamming, we hope you like jammin too At 03:09 PM 5/11/04 +0200, Eugen Leitl wrote: The second covers a hacking the system concept. I'd considered something similar myself, though different in approach. Rather than finding RFID chips and redistributing them, why not create programmable RFID broadcasters which could spoof other chips, and distribute these. The idea being to pollute any RFID detectors with a vast spew of superfluous data. RFID jamming should be very easy and a quite amusing DoS attack on commercial targets. Easy because its not frequency hopping, low power, and relatively low frequency. Particularly cute would be transmitting sex-toy codes intermittently. ASK any Elmer you happen to see, what's the best jamming, RFID.. (With apologies to the tuna industry and those too young to know the jingle. Or to know the RF double meanings.)
Re: We're jamming, we're jamming, we hope you like jammin too
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Major Variola (ret) wrote: | RFID jamming should be very easy and a quite amusing DoS attack | on commercial targets. Easy because its not frequency hopping, low | power, and relatively low frequency. Particularly cute would be | transmitting sex-toy codes intermittently. I would almost bet money that the commercial interests currently evaluating RFID tags will push for a legislative ban on RFID jamming. And I'll bet they get it too. Ian. -BEGIN PGP SIGNATURE- Version: GnuPG v1.2.4 (MingW32) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFAooY0SVC5oflyiAIRApAQAKCSflfED0AYd25kF6oUJZ8cffm7GACgj73q JrFT7ErGpPnGdSZMLFJgPd0= =PrA0 -END PGP SIGNATURE-
Re: We're jamming, we're jamming, we hope you like jammin too
ASK any Elmer you happen to see, what's the best jamming, RFID.. (With apologies to the tuna industry and those too young to know the jingle. Or to know the RF double meanings.) Interesting cultural reference that goes entirely above my head with a cute swooshing sound. Care to explain, please? :) I hope the subject line was not too obscure, mon. ASK = amplitude shift keying, which I believe is the RFID modulation Elmer = guru/wizard/elder in HAMspeak Jingle: Ask any mermaid you happen to see, what's the best tuna? Chicken of the sea. Ie, fish in cans. Sorry Charlie. Charlie don't surf, but that's because tuna cans don't give enough forward gain. Tying knots in the cultural web, MV
Re: We're jamming, we're jamming, we hope you like jammin too
RFID jamming should be very easy and a quite amusing DoS attack on commercial targets. Easy because its not frequency hopping, low power, and relatively low frequency. Particularly cute would be transmitting sex-toy codes intermittently. Considering the transmitting powers of the tags, an active battery-powered transmitter with a suitable antenna could have rather long range. A small circuit with a battery could be magnetically attached to a car of a selected victim and switched on after a delay, resulting in a mobile jamming platform. Parking lots in front of the stores, where there is often a direct line of sight between the cash registers and the cars, are especially suitable for this kind of attack. ASK any Elmer you happen to see, what's the best jamming, RFID.. (With apologies to the tuna industry and those too young to know the jingle. Or to know the RF double meanings.) Interesting cultural reference that goes entirely above my head with a cute swooshing sound. Care to explain, please? :) For personal defense, I came up with a similar, smaller-range and lower-power idea: - Micropower RFID jammer Very-low power passive/active jammer of passive RFID tags Radiofrequency tags bring a wide variety of privacy-related concerns. A semi-passive jammer may be an option to alleviate some of them. The tags are powered from the electromagnetic field the reader irradiates them with, then they transmit back on another frequency. The transmission takes some time, I guess few milliseconds, and is detectable by a nearby receiver. The tags are made in two kinds: plain, and more advanced collision-resistant ones. The first kind transmits blindly whenever powered, repeating its signature over and over, which causes two tags within the field of one reader to jam each other, as their responses get mixed together. The second, more expensive kind, uses algorithms to avoid the situation when two tags transmit at the same time, overlapping their responses and making them difficult to recognize; most often detecting another tag transmitting, and then going silent for random amount of time. This behavior makes it possible to design a micropower jammer. The device shall listen on the frequencies both the readers and the tags transmit on. When the tag read attempt is detected, the device owner may be alerted - by a LED, a sound, a vibration. Then when the device detects the tag's attempt to answer, it broadcasts pulses looking like the answer of another tag, forcing a collision and a misread into every answer. The tiny power required for occassional transmitting of few very short pulses makes the device unlikely to cause other kinds of trouble, while additionaly making it less easy to be detected if declared illegal than continuous jammers.
Illuminating Blacked-Out Words
http://www.nytimes.com/2004/05/10/technology/10crypto.html?pagewanted=printposition= The New York Times May 10, 2004 Illuminating Blacked-Out Words By JOHN MARKOFF European researchers at a security conference in Switzerland last week demonstrated computer-based techniques that can identify blacked-out words and phrases in confidential documents. The researchers showed their software at the conference, the Eurocrypt, by analyzing a presidential briefing memorandum released in April to the commission investigating the Sept. 11 attacks. After analyzing the document, they said they had high confidence the word Egyptian had been blacked out in a passage describing the source of an intelligence report stating that Osama Bin Ladin was planning an attack in the United States. The researchers, David Naccache, the director of an information security lab for Gemplus S.A., a Luxembourg-based maker of banking and security cards, and Claire Whelan, a computer science graduate student at Dublin City University in Ireland, also applied the technique to a confidential Defense Department memorandum on Iraqi military use of Hughes helicopters. They said that although the name of a country had been blacked out in that memorandum, their software showed that it was highly likely the document named South Korea as having helped the Iraqis. The challenge of identifying blacked-out words came to Mr. Naccache as he watched television news on Easter weekend, he said in a telephone interview last Friday. The pictures of the blacked-out words appeared on my screen, and it piqued my interest as a cryptographer, he said. He then discussed possible solutions to the problem with Ms. Whelan, whom he is supervising as a graduate adviser, and she quickly designed a series of software programs to use in analyzing the documents. Although Mr. Naccache is the director of Gemplus, a large information security laboratory, he said that the research was done independently from his work there. The technique he and Ms. Whelan developed involves first using a program to realign the document, which had been placed on a copying machine at a slight angle. They determined that the document had been tilted by about half a degree. By realigning the document it was possible to use another program Ms. Whelan had written to determine that it had been formatted in the Arial font. Next, they found the number of pixels that had been blacked out in the sentence: An Egyptian Islamic Jihad (EIJ) operative told an service at the same time that Bin Ladin was planning to exploit the operative's access to the US to mount a terrorist strike. They then used a computer to determine the pixel length of words in the dictionary when written in the Arial font. The program rejected all of the words that were not within three pixels of the length of the word that was probably under the blackened-out area in the document. The software then reduced the number of possible words to just 7 from 1,530 by using semantic guidelines, including the grammatical context. The researchers selected the word Egyptian from the seven possible words, rejecting Ukrainian and Ugandan, because those countries would be less likely to have such information. After the presentation at Eurocrypt, the researchers discussed possible measures that government agencies could take to make identifying blacked-out words more difficult, Mr. Naccache said in the phone interview. One possibility, he said, would be for agencies to use optical character recognition technology to rescan documents and alter fonts. In January, the State Department required that its documents use a more modern font, Times New Roman, instead of Courier, Mr. Naccache said. Because Courier is a monospace font, in which all letters are of the same width, it is harder to decipher with the computer technique. There is no indication that the State Department knew that. Experts on the Freedom of Information Act said they feared the computer technique might be used as an excuse by government agencies to release even more restricted versions of documents. They have exposed a technique that may now become less and less useful as a result, said Steven Aftergood, a senior research analyst at the Federation of American Scientists, of the research project. We care because there are all kinds of things withheld by government agencies improperly. -- - R. A. Hettinga mailto: [EMAIL PROTECTED] The Internet Bearer Underwriting Corporation http://www.ibuc.com/ 44 Farquhar Street, Boston, MA 02131 USA ... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience. -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
