December 2003 - cypherpunks-legacy

Re: 40-bit RC5 crack meaningless??
by nobody＠REPLAY.COM 17 Dec '03

17 Dec '03

Over on sci.crypt, Paul C. Kocker <pck(a)netcom.com> gave a clear and confident response to a query about the statistical difference between a brute force attack on a known Russian or English text, versus a similar attack on cyphertext with a known-plaintext sample (Strassmann's tell-tale Clue #3.) Said Kocher: The difference is negligable. With English text encrypted under a 64-bit block cipher, you know that the most significant bit of each of the 8 bytes in the block should be zero. For a wrong key, there is a 255/256 probability that at least one of these bits will be nonzero, allowing immediate rejection of the key. Keys which do produce all zero bits get tested on additional blocks until the key is either deemed correct or rejected. The extra overhead per wrong key is the sum from i=1 to infinity of i*(1/256^i), or under 0.4 percent. In practice, the slowdown is actually a couple of percent, since it complicates the skip-the-last-Fiestel-round optimization. Also, the 1/256 case requires running extra code, which can fill the microprocessor's cache with code which isn't part of the main loop, slowing things down a bit when the computer goes back to the main search. Cheers, Paul ____________________________________ http://www.cryptography.com Paul Kocher (pck(a)netcom.com) | Voicemail: +1-(415)-354-8004 Crypto consultant | FAX: +1-(415)-321-1483

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ISPs vs Bells - Email FCC
by Derrick Storren 17 Dec '03

17 Dec '03

Baby Bells want us to pay by the minute. An opportunity to tell the FCC what we think via email at isp(a)fcc.gov -- article follows. ***************************************** By Michelle V. Rafter LOS ANGELES - Regional phone companies and Internet service providers are waging a war of words over Internet traffic on the nation's local telephone network and who should pay for upgrades as the online boom continues. As a drama, the phone companies vs. Internet providers contest is dry, complicated stuff, lacking the sex appeal of, say, the power struggle between Netscape and Microsoft for control of the personal computer desktop. Even so, analysts and other industry watchers counsel consumers and businesses to take heed of the tug of war because it could affect how much they pay to use the Internet, and ultimately, how they connect to it. In one corner, Pacific Bell, Bell Atlantic and other regional phone carriers say the growth of Internet traffic is pushing local telephone networks to the breaking point. Pacific Bell, for example, says Internet surfers use its phone lines an average of 45 minutes a day -- more than twice the amount the network was built to handle. Heavy Internet use in Silicon Valley led to brief service outages in that area earlier this year, the company said. Pacific Bell and other local phone companies say they've poured millions of dollars into hardware improvements as a result of Internet traffic, improvements they claim would otherwise have been unnecessary. To help defray costs, phone companies think providers should pay for service on a per-minute basis, the way long-distance companies do, rather than by the line, like other business phone customers. Internet providers have been exempt from paying so-called access fees under a 1983 federal ruling meant to foster growth of compute data networks. On the other side, Internet service providers say phone companies have it all wrong. A recent report sponsored by the Internet Access Coalition, an industry lobby group, maintains computer traffic poses no threat to local phone networks and that earlier phone-company studies identifying trouble spots were based on theoretical claims and a few areas with engineering and planning problems that could easily be rectified. If Internet traffic was such a threat, phone companies wouldn't be exacerbating the problem by jumping into the Internet access business themselves, providers say. Rather than hurting phone companies, Internet traffic has been a windfall, according to the coalition. In 1995, local phone companies spent a total of $245 million adding 6 million residential phone lines used primarily for Internet access, but reaped $1.4 billion in revenue on those lines, the group said. If providers are required to pay access fees, they'll have no choice but to raise their rates, which could stifle Internet growth just as it's taking off, they say. Internet providers and phone companies are arguing their respective positions in Washington, where the Federal Communications Commission is considering the access-fee issue. As part of ongoing telecommunication industry reform, the FCC said in late December it would cut access fees levied on long-distance carriers and is investigating options for doing that. But the agency held off making a decision affecting Internet use to allow time for parties with an interest in the issue to present their cases. The FCC took the unusual step of setting up an e-mail address -- isp(a)fcc.gov -- consumers and others can use to send their thoughts. Internet providers and phone companies have until Feb. 21 to submit formal comments, and the agency is expected to make a ruling later this year. Even if the FCC levies access fees on providers and companies raise rates accordingly, it won't dampen consumers' love affair with the Internet, some analysts said. If, for example, Internet providers passed through an access fee of 1 cent a minute, a subscriber spending 10 hours online a month would pay an extra $6 -- hardly a deterrent, said David Goodtree, an analyst with Forrester Research in Cambridge, Mass. "Cable TV rates have doubled in the last three or four years, we got nothing more for it, but cable subscribership didn't go down because of it," Goodtree said. On one point everyone agrees -- the nation's current analog telephone network eventually will not be able to handle demand from Internet users, and must be supplanted by a digital system better suited to transmitting computer data. Both phone companies and Internet providers have begun working on solutions. Phone carriers that have offered digital ISDN (integrated services digital network) lines are stepping up their marketing efforts. Phone companies and Internet providers are investigating a new technology called digital subscriber line, or DSL, which routes Internet phone traffic around analog phone-company switches into all-digital networks. But inevitably, discussion of DSL and other new technologies circles back to who'll pay for upgrades. Sky Dayton, president of Internet provider Earthlink Networks in Pasadena, Calif., believes it is in phone companies' best interests to spend on digital upgrades because of the profit potential from selling them to companies such as his. But why should phone companies pick up all the costs when Internet service providers will benefit, too, says Pacific Bell spokesman Bob Deward. (Michelle V. Rafter writes about cyberspace and technology from Los Angeles. Reach her at mvrafter(a)deltanet.com. Opinions expressed in this column are her own.) Copyright, Reuters Ltd. All rights reserved

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Re: Govt & cyberspace
by Dale Thorn 17 Dec '03

17 Dec '03

Declan McCullagh wrote: > I find your "distributed democracy" interesting, except that it would > allow scant time for deliberation. Think of it this way: don't you > think the majority of Americans would have voted to pass the CDA? > Or worse? Or restrictions on domestic crypto? Or worse? > Democracy generally means majoritarian rule. The Bill of Rights is an > anti-majoritarian document. It protects the rights of political or > religious minorities. I fear that electronic "click here to vote" > democracy would undermine the Bill of Rights even more. You spoke a key phrase when you said "scant time". When I was in the Perot camp, I saw some direct "democracy" in action, and it was pitiful how the little folks could be herded into voting this way and that. OTOH, this subject deserves more in-depth analysis, and a good starting point could be the California referendums (Prop. 209, etc.), followed on by Supreme Court decisions saying OK, not OK, and so on. That system provides a good mix of people having input and proper Constitutional judicial review. One of the good factors is the pamphlets the state sends out to voters prior to the election, with a decent analysis of the issues from opposing points of view. Not perfect to be sure, but a good start. > Dale Thorn writes: > I wish for once and for all someone would delineate this "democracy" > thing from a true, distributed democracy, where every individual is > required to participate equally, and no narrow interests can co-opt > the vote the way they do in the kind of "democracy" Declan mentions.

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Appointment Verification
by inc＠jps.net 17 Dec '03

17 Dec '03

Suck_My_Big_Juicy_Cock, We would like to ask for your help with a survey for a service bureau we are considering developing software for in voice communications. This software will be used to remind patients of their upcoming appointments, allow them to confirm or reschedule. After confirming which patients will not be able to make their appointment the system will contact all individuals that are on a waiting list to schedule them for open time slots..... For assisting us we will mail you a FREE certificate for 100 rolls of Kodak film and a 35 mm camera. NO ONE WIll CALL YOU! 1. Do you feel doctors would use a service which calls patients for them using a personalized Voice system reminding them of their appointments? ____yes ____NO 2. How important do you feel it is to doctors to eliminate the drudgery of staff calling patients reminding them of appointments. not important ______ somewhat important ______ Very important ______ 3. What's do you feel would be a fair price or doctors would be willing to pay for such a service? 100-$200 per month _____ 200-$300 per month _____ 300- $400 per month _____ Other ____________ Please email your answers to advance(a)ns.net If you have any suggestions on any additional automated voice service you would like to see someone develop please let us know. Thanks again for your participation.

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Re: 40-bit RC5 crack meaningless??
by Anonymous 17 Dec '03

17 Dec '03

Over on sci.crypt, Paul C. Kocker <pck(a)netcom.com> gave a clear and confident response to a query about the statistical difference between a brute force attack on a known Russian or English text, versus a similar attack on cyphertext with a known-plaintext sample (Strassmann's tell-tale Clue #3.) Said Kocher: The difference is negligable. With English text encrypted under a 64-bit block cipher, you know that the most significant bit of each of the 8 bytes in the block should be zero. For a wrong key, there is a 255/256 probability that at least one of these bits will be nonzero, allowing immediate rejection of the key. Keys which do produce all zero bits get tested on additional blocks until the key is either deemed correct or rejected. The extra overhead per wrong key is the sum from i=1 to infinity of i*(1/256^i), or under 0.4 percent. In practice, the slowdown is actually a couple of percent, since it complicates the skip-the-last-Fiestel-round optimization. Also, the 1/256 case requires running extra code, which can fill the microprocessor's cache with code which isn't part of the main loop, slowing things down a bit when the computer goes back to the main search. Cheers, Paul ____________________________________ http://www.cryptography.com Paul Kocher (pck(a)netcom.com) | Voicemail: +1-(415)-354-8004 Crypto consultant | FAX: +1-(415)-321-1483

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Re: Moderation, Tim, Sandy, me, etc. * Strong crypto == DES?!
by C Matthew Curtin 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- >>>>> "Jeff" == Jeff Barber <jeffb(a)issl.atl.hp.com> writes: John> Tim, the Cypherpunks have chosen to follow Sandy's lead for this John> month. I'll admit I made it easy for them, but the results are John> conclusive. There are 1311 addresses in the cypherpunks list John> today; 42 in the unedited list; and 19 in the flames list. Jeff> "Conclusively" this has shown only that most folks are willing Jeff> to go along with an experiment -- especially if it requires them Jeff> to do exactly nothing. This is precisely the category into which I fall. It is a pain to unsubscribe from a list, since my "From_" header doesn't agree with my "From:" header (the former has a specific host included, the latter only a zone), and this often triggers a message to the list owner for processing. In any case, I am willing to go along with the experiment. But a NoCeM-style approach to killing the noise is much more preferable. Failing that, an individual filter (such as procmail) is good. In any event, the responsibility of what to post and what to read should be in the hands of each reder individually. - -- Matt Curtin Chief Scientist Megasoft, Inc. cmcurtin(a)research.megasoft.com http://www.research.megasoft.com/people/cmcurtin/ I speak only for myself Hacker Security Firewall Crypto PGP Privacy Unix Perl Java Internet Intranet -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Have you encrypted your data today? iQEVAwUBMvtGmH6R34u/f3zNAQFQbwf9HYoT51vkHSjSJOnzXcphD7WLoOEq8WV1 rj33PUweZiibTyZg1JADdbS09QVgl80TE90YDJGQ/c77wwBuMKiJTVAz8jaixjCK kUJ6IiQ4Ul3Q1LfyM5iC/kphQc/ILld0PHpaZl104pLoJ13rK6FCzMaQd+MZpWoJ ZLWxrKaebFF5IH0dW9avJ3Vb5Kp+6OSGmpBwooFiq+nhuUCaeAZtOAwmutDM5d1g oDTXGmdFuDLzjAuLcQnNAwc/nRd0bBLj3b3KFYkOzNjnl3BjOw3s4XVMF4sELOCX aOnxZE/u7lP3HkAQtJ+PxHgthUbODE0ixDU0iuWSrDVm8gRAe4Xm0A== =78/T -----END PGP SIGNATURE-----

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ISPs vs Bells - Email FCC
by Derrick Storren 17 Dec '03

17 Dec '03

Baby Bells want us to pay by the minute. An opportunity to tell the FCC what we think via email at isp(a)fcc.gov -- article follows. ***************************************** By Michelle V. Rafter LOS ANGELES - Regional phone companies and Internet service providers are waging a war of words over Internet traffic on the nation's local telephone network and who should pay for upgrades as the online boom continues. As a drama, the phone companies vs. Internet providers contest is dry, complicated stuff, lacking the sex appeal of, say, the power struggle between Netscape and Microsoft for control of the personal computer desktop. Even so, analysts and other industry watchers counsel consumers and businesses to take heed of the tug of war because it could affect how much they pay to use the Internet, and ultimately, how they connect to it. In one corner, Pacific Bell, Bell Atlantic and other regional phone carriers say the growth of Internet traffic is pushing local telephone networks to the breaking point. Pacific Bell, for example, says Internet surfers use its phone lines an average of 45 minutes a day -- more than twice the amount the network was built to handle. Heavy Internet use in Silicon Valley led to brief service outages in that area earlier this year, the company said. Pacific Bell and other local phone companies say they've poured millions of dollars into hardware improvements as a result of Internet traffic, improvements they claim would otherwise have been unnecessary. To help defray costs, phone companies think providers should pay for service on a per-minute basis, the way long-distance companies do, rather than by the line, like other business phone customers. Internet providers have been exempt from paying so-called access fees under a 1983 federal ruling meant to foster growth of compute data networks. On the other side, Internet service providers say phone companies have it all wrong. A recent report sponsored by the Internet Access Coalition, an industry lobby group, maintains computer traffic poses no threat to local phone networks and that earlier phone-company studies identifying trouble spots were based on theoretical claims and a few areas with engineering and planning problems that could easily be rectified. If Internet traffic was such a threat, phone companies wouldn't be exacerbating the problem by jumping into the Internet access business themselves, providers say. Rather than hurting phone companies, Internet traffic has been a windfall, according to the coalition. In 1995, local phone companies spent a total of $245 million adding 6 million residential phone lines used primarily for Internet access, but reaped $1.4 billion in revenue on those lines, the group said. If providers are required to pay access fees, they'll have no choice but to raise their rates, which could stifle Internet growth just as it's taking off, they say. Internet providers and phone companies are arguing their respective positions in Washington, where the Federal Communications Commission is considering the access-fee issue. As part of ongoing telecommunication industry reform, the FCC said in late December it would cut access fees levied on long-distance carriers and is investigating options for doing that. But the agency held off making a decision affecting Internet use to allow time for parties with an interest in the issue to present their cases. The FCC took the unusual step of setting up an e-mail address -- isp(a)fcc.gov -- consumers and others can use to send their thoughts. Internet providers and phone companies have until Feb. 21 to submit formal comments, and the agency is expected to make a ruling later this year. Even if the FCC levies access fees on providers and companies raise rates accordingly, it won't dampen consumers' love affair with the Internet, some analysts said. If, for example, Internet providers passed through an access fee of 1 cent a minute, a subscriber spending 10 hours online a month would pay an extra $6 -- hardly a deterrent, said David Goodtree, an analyst with Forrester Research in Cambridge, Mass. "Cable TV rates have doubled in the last three or four years, we got nothing more for it, but cable subscribership didn't go down because of it," Goodtree said. On one point everyone agrees -- the nation's current analog telephone network eventually will not be able to handle demand from Internet users, and must be supplanted by a digital system better suited to transmitting computer data. Both phone companies and Internet providers have begun working on solutions. Phone carriers that have offered digital ISDN (integrated services digital network) lines are stepping up their marketing efforts. Phone companies and Internet providers are investigating a new technology called digital subscriber line, or DSL, which routes Internet phone traffic around analog phone-company switches into all-digital networks. But inevitably, discussion of DSL and other new technologies circles back to who'll pay for upgrades. Sky Dayton, president of Internet provider Earthlink Networks in Pasadena, Calif., believes it is in phone companies' best interests to spend on digital upgrades because of the profit potential from selling them to companies such as his. But why should phone companies pick up all the costs when Internet service providers will benefit, too, says Pacific Bell spokesman Bob Deward. (Michelle V. Rafter writes about cyberspace and technology from Los Angeles. Reach her at mvrafter(a)deltanet.com. Opinions expressed in this column are her own.) Copyright, Reuters Ltd. All rights reserved

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Re: anonymous remailers
by Chuck Fender 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- At 05:40 PM 2/6/97 -0500, you wrote: > >c.musselman(a)internetmci.com (Charley Musselman) writes: >> C'punks -- >> When I told a friend about the alt.drugs.pot cultivation newsgroup >> and suggested that he use an anonymous remailer to post to the group, >> he laughed and said, "Who do you suppose runs the remailers? ATF, >> FBI, DEA, that's who!" Gee, it makes sense to this paranoid. Does >> anyone know the answer? Specifically, how can we choose a trusted >> remailer? > >The solution is not to choose a trusted remailer, but to choose a >group of remailers and send your message through each one I run an anonymous remailer. I have a mixmaster type at mix(a)wazoo.com nd a cypherpunk type at remailer(a)wazoo.com. Also, there is a WWW interface at http://www.wazoo.com/~remailer. I know that my system doesn't keep any recorders except number of messages that go through. I am a "secure remailer". Before I set up the remailer, I did a lot of soul searching, knowing that somewhere along the road I could help a "baby raper" or something else I find morally objectionable. I came to the conclusion, and I still think it is the right conclusion, that the public service offered by an anonymous remailer far outweighs the disadvantages of potentially helping someone I personally find objectionable. Setting up a remailer, for someone that is already running a domain, is easy enough to be almost trivial. With the explosion of domains the internet has seen in the past couple of years, at least some of the remailers have to be honest and not fronts for the DOJ, FBI, and whatever other alphabet orginizations... Obviously, you are thinking that any FBI agent that wanted to could post this exact message, and YOU ARE RIGHT! Take advantage of a string of remailers. Use proper encryption, so that none of them know more than the next hop. Make sure you vary the order of remailers you go through with each message. Being cautious, you can be almost 100% certain your message is anonymous. Chuck Sys Admin... Wazoo's Computers ====================================== PGP key for remailer(a)wazoo.com available from all public key servers of by fingering: remailer@wazoo.com...help file available by sending mail to remailer(a)wazoo.com with a subject of remailer-help ====================================== For those that missed or already deleted the list, here are some places to find more about remailers: http://WWW.CSUA.Berkeley.EDU/cypherpunks/remailer/ http://www.stack.nl/~galactus/remailers/index-anon.html http://www.cs.berkeley.edu/~raph/remailer-list.html -----BEGIN PGP SIGNATURE----- Version: 4.5 Comment: Chuck Fender <<chuck(a)wazoo.com> Sys Admin for Wazoo's Computers iQCVAgUBMvtCni/mzwsxwvO5AQGbjgP/d8YfoPxHnSG4Gu6G/3Vx7GcPFK6DBj4Z FtdoNdQUgWFrMK270Ep6dz5wBIGiEJrPNpiMJQJl2mt4GRSP4RTT3zWy1T8ULclr wFnywwjieMFxyz4JBBGbyBssNZM2OqUSJIyMFXWdmQyXTKNOXqxnW9oMOu82QqLD TuHUSUaxrYU= =rJFq -----END PGP SIGNATURE----- <color><param>0000,0000,8080</param>***************************************** * </color> <bold><color><param>0000,0000,ffff</param>Wazoo's Computers </color></bold><color><param>0000,0000,8080</param>* *</color> Alamogordo's Internet Access Provider <color><param>0000,0000,8080</param>* *</color> <color><param>ffff,0000,0000</param>(505) 434-5090 </color><color><param>0000,0000,8080</param>* *****************************************</color>

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Re: 40-bit RC5 crack meaningless??
by John Young 17 Dec '03

17 Dec '03

Paul Strassmann served on the "Information Warefare - Defense" Task Force sponsored by the Defense Science Board. He has a Web site at: http://www.strassmann.com The IW-D report recounts most of the well-known info-war memes to buttress its plea for more info-warfighting funds, and says that business needs DoD protection. It de-emphasizes the encryption debate, claiming that crypto is not an important part of the problem or the solution. Remailers are not mentioned. Short and long versions of IW-D: http://jya.com/iwd.htm Winn Schwartau's infowar.com offers it too. SAIC was generously represented on the Task Force: Strassmann, Bellcore's head, a couple more. As well as others committed to "raising the bar" against attack on Info-Maginot: http://jya.com/iwdaff.htm

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Re: 40-bit RC5 crack meaningless?
by Peter Trei 17 Dec '03

17 Dec '03

Subject: Re: 40-bit RC5 crack meaningless?? From: Peter Trei <ptrei(a)acm.org> > Subject: 40-bit RC5 crack meaningless?? Mr. Strassman allegedly sent the quoted letter to Winn Schwartaus' "infowar" mailing list, and it was then posted by persons unknown to the sci.crypt usenet group. Identity on the internet being the fluid thing it is, I apologize in advance if he never sent this letter, or if it has been modified before it reached me. The quoted letter attempts to minimize the importance of Ian Goldberg's recent bruteforce decryption of export-strength RC5 encryption. In my opinon, as described below, Mr. Strassman's arguments are without merit when applied to the situation the RSA challenges are intended to model - the security of encrypted Internet protocols. As such, I feel that his letter may lull some people into an unjustified and dangerous sense of security. > >Date: Thu, 30 Jan 1997 20:10:36 -0500 > >From: "Paul A. Strassmann" <paul(a)strassmann.com> > >Subject: Further to Goldberg's Cracking Accomplishments > >Gentlemen: > > > >As I suspected (see earlier private comment), the > >highly promoted RSA cracking contest offered > >a number of clues that ordinarly would not be > >volunteered by info-terrorists or info-criminals to > >IW Defense teams. > >These clues made the cracking significantly easier, > >because it made it possible to eliminate an enormous > >range of possible searches. What's the target, and who is doing the encrypting? These "clues" _are_ available to adversaries engaged in industrial and economic espionage; a important part of a covert infowar. It's certainly true that "info-terrorists or info-criminals" will not be so easy to tap, but the absence of these 'clues' is a red herring. They will be secure because they will use good encryption, which is not what US firms can export today. The challenges are realistic models of encrypted Internet protocols, for example IPSEC with ESP data encryption. As such, they accurately display the vulnerability of data on the Internet to espionage. > >The following was extracted verbatim from the > ><The RSA Data Security Secret-Key Challenge> > >posted on <http://www.rsa.com/rsalabs/97challenge/>: > > > >Clue #1: > > > > " ...all the RC5 contests posted as part of the RSA Secret-Key Challenge > >will use 12-round RC5 with a 32-bit word size. " > > > >Clue #2: > > > > " ...The first RC5 contest will consist of some unknown plaintext > >encrypted using a 40-bit key;." Clues #1 and #2 are absolutely reasonable - in an open standard, it is absolutely normal to know the cipher being used, it's mode, and the length of the key. See the SSL specification, or IPSEC's RFCs. > >Clue #3: (a giveway!) > > > > " ... For each contest, the unknown plaintext message is preceded by three > > known blocks of text that contain the 24-character phrase "The > > unknown message is: .....". To those who are unfamiliar with Internet protocols, this would appear to give the cryptanalyst an unrealistic head-start. This is not the case. Most Internet protocols have highly stereotyped packet headers; for example, _every_ normal return packet from a web server starts out with the string "HTTP/1.0" (servers using something other than version 1.0 are rare as hen's teeth at the moment). When you consider that such a packet may contain a firm's confidential earnings predictions or trade secrets (hopefully encrypted), the economic importance of such data is clear. Similar stereotyped headers exist for many other protocols, such as NNTP and SMTP. As such, a known-plaintext attack, as modeled by RSADSI's symmetric key challange, is quite realistic. Even if a full known plaintext for the first block is unavailable, a knowlegable cryptanalyst can usually make some very reasonable assumptions which will greatly speed his or her task. (I'm assuming DES here - which has a 64 bit block, but the argument extends easily to other block sizes). For example, if we know that the data contains only printable ASCII characters (true for the headers of most Internet protocols), then for a 64 bit block, there are 8 bits which we _know_ will be zero in the decrypted block. This lets us dispose of 255 out of every 256 incorrect trial decryptions immediately, and we will have to perform more extensive tests on less then 0.4% of candidate keys. Similar intelligent guesses can be made about the headers of other protocols, for example IPSEC-secured IPv6 packet headers in tunneling mode. Some people have noted that the challenges include the IV, or 'initialization vector' used in CBC (cipher-block-chaining) modes of encryption, and argue that this would not be available to an adversary. Once again, this assertion falls when examined in the light of actual usage. The purpose of an IV is to make dictionary and replay attacks more difficult. It is not intended to prevent brute force attacks, and so is _normally_ included in the clear in communications protocols (for example, see RFC 1827 for it's clear transmission in IPSEC). If it is not included, it is effectively part of the keying material, and thus adds it's bits to the strength of the key. As such, its value would have to be transmitted and protected as carefully as the rest of the key. > >In summary: The claim of exportable cryptography being totally > >insecure, because it can be cracked in 3.5 hours is not > >realistic. The three clues announced in the contest > >would not apply under infowar conditions. As I have shown above, Mr. Strassman's optimism is misplaced in the case of actual, fielded use of encryption on the Internet. It may apply to some classified systems, but they don't use exportable cryptography anyway. A covert inforwar against commercial and private targets is _quite_ plausible. > >What other clues may have been provided to Goldberg > >to support private agendas and gain shrill headlines > >is also a matter of speculation, but I rest my case. What exactly is he hinting at here? > >I certainly cannot assert that a 40 bit key cannot be decyphered. Of course he can't. 40 bits of RC4 encryption (as used in the exportable version of Netscape) was brute-forced not once, but three separate times in the fall of 1995, the fastest effort taking about 28 hours. Today it could be done much more quickly, as Ian demonstrated with RC5 (an algorithm of similar complexity). > >However, I do not think that the RSA unqualified claims > >offer full and appropriate disclosure. I disagree. The RSA challenges accurately model the use of encryption on the unclassified Internet. Ian's decryption of 40-bit RC5 is of considerable importance in demonstrating the insecurity of American citizens caused by Administration efforts to compromise exportable encryption. In my opinon, Mr. Strassman's assertions as to the strength of exportable encryption are too dangerous to be left unchallenged. > >Paul A. Strassmann > >55 Talmadge Hill Road, New Canaan, CT. 06840 > >Telephone: 203-966-5505; Fax: 203-966-5506 > >INTERNET: paul(a)strassmann.com > >WorldwideWeb: http://www.strassmann.com Peter Trei ptrei(a)acm.org Disclaimer: I am speaking as a knowlegable private citizen, not as a representative of my employer. This posting represents my opinon only.

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