- cypherpunks-legacy - lists.cpunks.org

Randomness
by pmetzger＠shearson.com 27 Jan '93

27 Jan '93

> From: thug(a)phantom.com (Murdering Thug) > > Yes I do think the idea of making a "more random than random" stream > by filtering out long runs of 0's or 1's weakens the the key stream > in theory, but in practical use it strengthens it, because if the stream > is left alone, runs of 500 bits of 0's or 1's can come through, and any > fool can then extract plain text using XOR in this area of the cyphertext. The odds against a run of 500 1's is one in 2^500th, which is a number so large I can't imagine a real random number source creating it in the lifetime of our universe. Presumably, your problem is that your random number source is crap. Perry

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Re: Computerized OTP (was 5th AMENDMENT & DECRYPTION)
by nobody＠alumni.cco.caltech.edu 27 Jan '93

27 Jan '93

Murdering Thug wrote: > Yes I do think the idea of making a "more random than random" stream > by filtering out long runs of 0's or 1's weakens the the key stream > in theory, but in practical use it strengthens it, because if the stream > is left alone, runs of 500 bits of 0's or 1's can come through, and any > fool can then extract plain text using XOR in this area of the cyphertext. Thug is wrong about this, but it's a common mistake. It does seem like those runs of 0's (and, to a lesser extent, 1's) are dangerous - there's your plaintext, totally exposed to the prying eyes of strangers! But, what is forgotten is this: for every run of 0's which would reveal your plaintext, there is an equally likely pattern of 1's and 0's which transforms your plaintext into one of Shakespeare's plays. Or into the Declaration of Independence. Or into anything else you like. You see, xor'ing your message with a random stream means that the resulting output is equally likely to be _any_ original message. There is no way in theory or in practice to determine what the message originally was; that is, all bit patterns are equally likely to be the original message. To see an example of this, suppose you had one of the simplest possible original messages: all 1's. Now you xor this with a random pattern. To your dismay, your random stream happens to come up with a large block of 0's. This is what would happen: Original message: 1111111111111111111111111111111111 Random stream: 0011010010000000110111010111001010 Resulting output: 1100101101111111001000101000110101 Look at that big block of 1's in there. Won't that give it away? No. Such a block of 1's is expected to occur occasionally no matter what the original message. It's just as likely that the original message and random stream looked like: Original message: 1010101010101010101010101010101010 Random stream: 0110000111010101100010000010011111 Resulting output: 1100101101111111001000101000110101 There is no way to tell what the original message was, even when you see a block of output which seems to match some pattern. It doesn't tell you anything. Hal 74076.1041(a)compuserve.com

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Random OTP sources
by Douglas Sinclair 27 Jan '93

27 Jan '93

Much discussion has been going on about creating a truly random OTP key by tuning in to dead TV channels, etc. There is a much simpler, and more secure way. Look at the decay of a small radioactive source. Find a time period in which there is a 50% chance of seeing an event, and then clock a 1 if you do, or a 0 of you don't. Radioactive sources and detectors are easily obtained from smoke detectors, and it should be fairly easy to set up (though I havn't done it). If our understanding of quantum mechanics are correct, the resulting bitstream is truly random. RF noise may be random. Also, if the NSA or other Big Brother organization knows what you are doing, they can try listening in on the same channel and deducing your key. To my knowledge, there is no way to see what is going on in a small Californium source if you have more than a few meters between the source and detector. Anyhow, a given event will probably only produce one particle, or maybe two, so your point detector will only see a portion of the events and knowledge of particles in another direction doesn't tell you anything. Hm. I hope that was coherent. Any comments? -- Vercotti: I was terrified of him. Everyone was terrified of Doug. I've seen grown men pull their own heads off rather than see Doug. Even Dinsdale was frightened of Doug. Interviewer: What did he do? Vercotti: He used sarcasm. He knew all the tricks, dramatic irony, metaphor, bathos, puns, parody, litotes and satire. -- Monty Python, Episode 14 PGP 2.1 Key by finger

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Re: a few good weasels
by edgar＠spectrx.Saigon.COM 27 Jan '93

27 Jan '93

Dave del Torto said here: A world of absolutes is not a fun world and it's not a safe world. Someone's gotta break the rules every once in a while or we all go down the tubes. Of course, I _personally_ would _never_ break any of the fine laws of our beloved nation, but I know deep in my heart (but not anywhere on my hard disks) that such brave people exist and that the effect of their less-than-legal efforts is the delicate equilibrium in which we continue to prosper and innovate. I agree completely. So would Ollie North, who is a fine example of "such brave people". -- edgar(a)spectrx.saigon.com (Edgar W. Swank) SPECTROX SYSTEMS +1.408.252.1005 Silicon Valley, Ca

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PRACTICAL DECRYPTION
by John.Nieder＠f33.n125.z1.FIDONET.ORG 27 Jan '93

27 Jan '93

from: john.nieder(a)f33.n125.z1.fidonet.com > (commenting on the strategy of "taking the 5th" on the matter of > decrypting one's files) > > > . Recently this question came up in another forum on encryption & an > > "authority" on communications law claimed the probable scenario would be > > that the arresting agency would have the encrypted material decrypted by > > a competent government or academic agency & the costs of said decryption > > would eventually be recovered from the defendant through civil suits, > > presuming the defendant had sufficient assets. It is my memory of the > > thread that he claimed this had been done in previous cases. > > With strong crypto, e.g., with 300 decimal digit moduli, the "costs" > of decryption by brute force could easily exceed the GNP/GDP of the > U.S. # Since none of us have ever been inside the NSA, we cannot underestimate # their power and resources. For all we know... This is somewhat beside the point. In actual fact, much of the seized encrypted evidence in criminal cases employs built-in encryption programs in major software packages (WordPerfect is a good example) rather than obscurer stuff like PGP/IDEA/RSA. Even highly-touted commercial programs like Norton Utilities DiskReet w/DES use simple passwords of a maximum ten-character size. . Much of this decryption may be trivially accomplished, though many "experts" charged law enforcement agencies stout fees for the service. It is now known that those specializing in WordPerfect files were using a simple program available on most BBS file bases which will crack the "secret" WordPerfect password in seconds on an old XT. . Apparently, the consulting fees for breaking bad crypto in most cases is not prohibitive. . Tim's objections about high-end decryption are indeed valid, at least theoretically, but we can not tell if a given encryption program has been backdoored or if a fatal flaw has been uncovered that reduces the security of the cyphertext. If any cryptanalysts might find such flaws, they would probably be those in no position to reveal their findings. . Jean-Loup Gailly [an original PGP team member in France] informs me that the same general criticisms of PGP soundness voiced in the Moscow State University report have been independently suggested in sci.crypto, though he is aware of no instance of these alleged weaknesses being exploited to break a PGP message. The jury is still out on PGP's ultimate security, I suppose. . Personally, I am not counting on PGP's brute-force decryption being a task of the magnitude Tim suggests, though I _hope_ he's right. I sure wish some well-equipped crypto labs like Marty Hellman's would turn their attentions to an evaluation of PGP... JN --- Blue Wave/Opus v2.12 [NR] -- John Nieder - via FidoNet node 1:125/555 UUCP - ...!uunet!hoptoad!kumr!fidogate!33!John.Nieder INTERNET - John.Nieder(a)f33.n125.z1.FIDONET.ORG

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SunExpress to expand "unlockable" software distribution
by gnu 27 Jan '93

27 Jan '93

It would probably be a public service if some interested parties were to determine the ``encryption'' method that Sun Express, the standard Sun ``license manager'', and other packages use. At the moment, the details of these technologies are not described in the public literature (as far as I know). Rather than have these companies discover years too late that their "unlockable" software is really unlockable by anyone who understands cryptography, it'd be better for them to learn it this year, while they are still handling low volumes of programs that way. Also maybe they will stop dumping these programs-that-you-have-but-must-pay-to-run on us. John ---------------------------------------------------------------------------- The Florida SunFlash SunExpress Unveils One-Stop Shopping From the Desktop SunFLASH Vol 49 #21 January 1993 ---------------------------------------------------------------------------- New CD-ROM and facsimile services make it easier than ever to select and purchase products CHELMSFORD, Mass. --January 26, 1993-- SunExpress, a subsidiary of workstation industry leader Sun Microsystems, Inc., today announced two new customer services which simplify information retrieval and product ordering. FaxInfo(SM), which allows SunExpress customers to access product information and order product through their fax machine, is available now. A second program will allow SunExpress customers to "unlock" software applications directly from SunSoft's Catalyst CDware(TM), the most widely-distributed demo CD for users of the UNIX(R) operating system. The CD-ROM program is being implemented in twenty customer sites on a trial basis and will be generally available later this year with Catalyst CDware Volume 5.0. The integration of these technologies, coupled with other electronic ordering innovations planned for release later in 1993, will allow SunExpress to process orders more efficiently and provide a higher level of customer satisfaction. Eventually, these process innovations will result in drastically fewer written orders, smaller inventories, less postage, phone and freight costs, resulting in reduced costs for SunExpress customers. "SunExpress is committed to providing its customers with leading-edge technologies that will make it easier than ever for them to select and purchase products. The new programs announced today are just the beginning," said Dorothy Terrell, president of SunExpress. "In the near future, our customers will be able to browse through full color on-line catalogs, watch video demonstrations and try out software all without leaving their workstation." FaxInfo The FaxInfo program allows SunExpress customers to access detailed product information about catalog offerings within minutes. By calling into the regular SunExpress ordering and information number (800-USE-SUNX), customers can access FaxInfo and have technical data sheets faxed back to the location of their choice by using the touch-tone keypad on their phone. SunExpress maintains up-to-date datasheets on all of the products that it offers and makes revisions to product specs as they are made available. SunExpress joins with SunSoft's Catalyst CDware Program Sun(TM) workstation users currently have access to SunSoft's Catalyst CDware program which allows them to run demo versions of a range of UNIX software applications from several major ISV's and decide whether it is something they would like to buy. With SunExpress' participation in the program, interested customers can purchase and obtain a fully-functional version of their chosen software -- all in one toll-free phone call. Currently this program is being tried out at twenty customer sites with limited software product offerings including: Clarity's Rapport(TM), and Ta-Dah!(TM) and SimCity(TM) from Dux Software. The program is targeted for full implementation with many more titles this summer, and will be attractive to ISVs who are already marketing their product through Catalyst CDware from SunSoft. Catalyst CDware currently carries 73 product presentations from 54 different vendors. "We feel that this service from SunExpress can only enhance the effectiveness and impact of our Catalyst CDware program," said Peter Schakow, Manager of CD programs at SunSoft. "We look forward to providing this added service to our Catalyst CDware partners." ISVs are interested in the SunExpress distribution strategy as a new sales channel. "This program will greatly facilitate our marketing efforts into the Sun installed base," said Bob Adams of DUX Software. "In addition to assisting with new product sales, it will be extremely useful and cost effective for distributing product enhancements and upgrades." SunExpress, a subsidiary of Sun Microsystems, Inc. provides customers with easy access to a wide range of Sun and innovative 3rd party products at low competitive prices and same day shipping. SunExpress supports SPARC(R), Solaris(R), and other computing environments based on the UNIX operating system. The company offers a 30-day no fault return policy and is currently serving customers in the United States, Europe and Japan. SunExpress can be reached at 1 (800) USE-SUNX and is headquartered in Chelmsford, MA. Press Contact: Hi-Tech Communications Mark Lederhos (508) 251-8278 Kathryn Lang (415) 904-7000 x204 Sun Lisa Ganier (415) 336-5637. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ For information send mail to info-sunflash(a)Sun.COM. Subscription requests should be sent to sunflash-request(a)Sun.COM. Archives are on solar.nova.edu, uunet.uu.net, sunsite.unc.edu, src.doc.ic.ac.uk and ftp.adelaide.edu.au All prices, availability, and other statements relating to Sun or third party products are valid in the U.S. only. Please contact your local Sales Representative for details of pricing and product availability in your region. Descriptions of, or references to products or publications within SunFlash does not imply an endorsement of that product or publication by Sun Microsystems. John McLaughlin, SunFlash editor, flash(a)Sun.COM. (305) 776-7770.

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Re: Computerized OTP (was 5th AMENDMENT & DECRYPTION)
by Marc.Ringuette＠GS80.SP.CS.CMU.EDU 27 Jan '93

27 Jan '93

Thug writes, > The other possibility is to find a truly random RF source that has all > the properties you want, the more important being that the >average< > length of a homogenous bit run (0's or 1's) is around 4 or 5 bits. "All the properties you want?" What you want is random, and nothing else! Random isn't "average bit runs of 4 or 5 bits". It isn't "nice white noise". It is TRULY RANDOM! You need to understand that the absolutely critical property for a one time pad bit-stream to have is this: given all previous bits seen, the probability that the next bit seen will be zero or one is exactly 0.5. What you need is a method for converting a biased random number stream (say, one where after a run of zeroes, another zero has high probability) into an unbiased one where the probability of the next bit being zero is exactly 0.5. Truncating runs to length 5 is an attempt at this, but a VERY BAD and cryptographically useless attempt. Does anybody remember a good recipe for converting a biased RNG into an unbiased one? I can't think of one off the top of my head, and that's what Thug's friend seems to need. This has been discussed at length in the literature. -- Marc Ringuette (mnr(a)cs.cmu.edu)

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5th Amendment and keys
by strat＠intercon.com 27 Jan '93

27 Jan '93

It might be worth pinging Mike Godwin for a summary of his current assessment. I was at a meeting with him over the weekend, and he said he's slowly growing more optimistic with regard to this very issue, as a result of some precedents he found. He'd probably be honored to know that a whole list was hanging on his every word. :-) --Strat

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[veritas!u.washington.edu!news@markv.com: ]
by Jay Prime Positive 27 Jan '93

27 Jan '93

From: jpp@hermix To: cypherpunks(a)toad.com Subject: [veritas!u.washington.edu!news(a)markv.com: ] Interesting message I recieved... Twice... j'

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weak point of PGP implementation
by The Phantom 27 Jan '93

27 Jan '93

tcmay says: ---- With strong crypto, e.g., with 300 decimal digit moduli, the "costs" of decryption by brute force could easily exceed the GNP/GDP of the U.S. ... bagged" the house, perhaps a simple pass phrase was used in lieu of memorizing 300 digits, and so on. ---- I've been wondering about this. It seems as though the weak point of PGP is one of three possible things: 1) RSA key length (a key length of 10 digits might be a good target, but noone using pgp uses anything so absurdly small, so this can be all but ruled out barring any huge jumps in factoring .. 2) 'conventional cryptography' used for encoding the secring.pgp files, etc. What crypto, exactly, is used? How strong is it? If the NSA knocked on the door and demanded your computer, would it try to crack your key, or would it go directly for the secring.pgp file? 3) length/triviality of pass phrase. This is, I would think, the weakest point mentioned yet. How long does the pass phrase have to be until this point becomes as secure as the weaker of the above two? If all bits of your passphrase were random, how long would an exhaustive search take? matt Matt Thomlinson University of Washington, Seattle, Washington. Internet: phantom(a)u.washington.edu phone: (206) 528-5732 PGP 2.0 key availaible via email or finger phantom(a)hardy.u.washington.edu

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