Re: RPOW - Reusable Proofs of Work
Matt Crawford writes: If you think of POW as a possible SPAM mitigation, how does the first receiving MTA assure the next MTA in line that a message was paid for? Certainly the mail relay doesn't want to do new work, but the second MTA doesn't know that the first isn't a spambot. The first MTA would exchange the received RPOW for a new one of equal value, and pass it along with the message to the next MTA in line. Hal - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: RPOW - Reusable Proofs of Work
At 04:34 PM 8/20/04 -0500, Matt Crawford wrote: I'm wondering how applicable RPOW is. If you think of POW as a possible SPAM mitigation As spam mitigation, it might work better than hashcash. As cash, it lacks the anonymity of bearer-documents (tm) since there is one clearing house. This might be improved via support for a system of mostly independent clearing houses which also interchange at interchange places. However, those would likely be regulated by the Powers That Be, ergo not alleviating my concerns about anonymity. My 2 dinars. = 36 Laurelwood Dr Irvine CA 92620-1299 VOX: (714) 544-9727 (home) mnemonic: P1G JIG WRAP ICBM: -117.7621, 33.7275 HTTP: http://68.5.216.23:81 (back up, but not 99.999% reliable) PGP PUBLIC KEY: by arrangement Send plain ASCII text not HTML lest ye be misquoted -- Don't 'sir' me, young man, you have no idea who you're dealing with Tommy Lee Jones, MIB No, you're not 'tripping', that is an emu ---Hank R. Hill - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
First quantum crypto bank transfer
--- begin forwarded text From: Andrew Thomas [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: First quantum crypto bank transfer Date: Fri, 20 Aug 2004 09:05:58 +0200 Sender: [EMAIL PROTECTED] Cryptography system goes underground (Aug 19) http://physicsweb.org/article/news/8/8/13 A group of scientists in Austria and Germany has installed an optical fibre quantum cryptography system under the streets of Vienna and used it to perform the first quantum secure bank wire transfer (A Poppe et al. 2004 Optics Express 12 3865). The quantum cryptography system consisted of a transmitter (Alice) at Vienna's City Hall and a receiver (Bob) at the headquarters of an Austrian bank. The sites were linked by 1.45 kilometres of single-mode optical fibre. -- Andrew G. Thomas --- end forwarded text -- - 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' - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
RFCs that reference MD5
I've made a number of modifications to my rfc index. if you go to the main url http://www.garlic.com/~lynn/rfcietff.htm you'll see a new note about list of RFCs that have some MD5 references in thier text (i.e. grep on md5 with some number of eliminations) the display is my standard summary format; if you click on the .txt= field it retrieves the actual RFC removed from the list are Obsoleted and/or Historic RFCs. I've also scanned (actually some gawk) all the RFCs attempting to recognize any References section and pull out list of referenced RFC numbers. That information is now added to the RFC summary listings ... in manner similar to the obsoletes/obsoletedby and updated/updatedby fields ... i.e. RFCs that are referenced by other RFCs now show the list of Ref'ed By). the summary listing for 1321 now looks like: 1321 I The MD5 Message-Digest Algorithm, Rivest R., 1992/04/16 (21pp) (.txt=35222) (Ref'ed By 1352, 1446, 1479, 1544, 1751, 1828, 1910, 1994, 2264, 2274, 2409, 2938, 3012, 3110, 3174, 3208, 3224, 3230, 3275, 3414, 3631, 3652, 3797) note that the RFCs mentioned md5 are more than the ones that include RFC 1321 in their references section (and/or I wasn't able to correctly recognize some references sections). -- Anne Lynn Wheelerhttp://www.garlic.com/~lynn/ - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: RPOW - Reusable Proofs of Work
It's like an online ecash system. Each recipient sends the RPOW back to the mint that issued it to ask if it has been double spent before accepting it as valid. If it's valid (not double spent) the RPOW server sends back a new RPOW for the receiving server to reuse. Very like Chaum's online ecash protocol, but with no blinding (for patent reasons) and using hashcash as way to buy coins. The other wrinkle is he can prove the mint can not issue coins without exchanging them for hashcash or previous issued coins (up to the limits of the effectiveness of the IBM tamper resistant processor card, and of course up to the limits of your trust in IBM not to sign hardware code signing keys that are not generated on board one of these cards). This is the same as the remote attestation feature used in Trustworthy Computing for opposite effect -- restricting what users can do with their computers; Hal is instead using this to have a verifiable server where the user can effectively audit and check what code it is running. Adam On Fri, Aug 20, 2004 at 04:34:00PM -0500, Matt Crawford wrote: I'm wondering how applicable RPOW is. Generally speaking, all the practical applications I can think of for a proof-of-work are defeated if proofs-of-work are storable, transferable, or reusable. I have some code to play online games with cryptographic protection, cards and dice, and I am planning to modify it to let people make bets with RPOWs as the betting chips. If you think of POW as a possible SPAM mitigation, how does the first receiving MTA assure the next MTA in line that a message was paid for? Certainly the mail relay doesn't want to do new work, but the second MTA doesn't know that the first isn't a spambot. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Good quote about the futility of ID-checking
Yeterday I watched Gillo Pontecorvo's 1966 film The Battle of Algiers, a dramatisation of real events that looks at France's own war on terror in Algeria in the 1950s. The police attempt to control things by only allowing people who can show valid ID into the european quarter of Algiers via a few checkpoints. When this proves completely ineffective, the French army, led by a Colonel Mathieu, is called in. The first thing he does is show his troops film footage of the checkpoints and the ID checking, pointing out that this footage is useful because it illustrates how not to do things: Checking identity papers is a complete waste of time. If anyone can be counted on to have valid papers, it will be the terrorists. That's actually a rather astute observation: Joe Sixpack will be lucky to remember to bring their passport, let alone check whether it's currently valid and every little detail is correct, but any terrorist will triple-check every bit of it to make sure that they don't get picked out. The best that the ID- checking can hope to do is stop opportunists (as well as any number of innocent Joe Sixpacks). Peter. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
