- cypherpunks-legacy - lists.cpunks.org

Re: Helping from Canada re Clipper
by Phil Karn 19 Jun '93

19 Jun '93

>Another argument the U.S. government is making is that they surveyed >encryption policy in various countries and "it's not beyond the pale >to limit domestic encryption -- France does it, for example". Is this an actual Administration quote? If so, they're playing with fire because France is the very same country that the US has recently accused of using its national security apparatus to spy on foreign corporations. It shouldn't be too hard to draw a link between these two policies that would cause this particular quote to blow up in the Administration's face. Phil

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Re: Blasting Bidzos Blather
by fnerd＠smds.com 18 Jun '93

18 Jun '93

Let's see if I understand L. Detweiler's recent comments: 1) PKP licensed key exchange for use with Clipper and DSS. Clipper and DSS are bad. Therefore PKP is "supporting, nay, *promoting* and *profiting* from" DSS and Clipper. a) "supporting, nay, *promoting*"--this is not good publicity against Clipper and DSS. Therefore PKP is our enemy. b) "*profiting from*"--this is dirty money, therefore PKP is dirty and we can't trust them. 2) They did it "at no additional charge." (Someone please explain relation to 1b, above.) Therefore they must be receiving some other compensation behind our backs. Therefore they're bad guys and we shouldn't trust them. 3) Bidzos says they don't dictate terms, yet their licenses DO have terms. Therefore he is lying, should not be trusted, etc. 4) They should have refused to license bad uses of "their" technology, but they didn't. Therefore they're bad, etc. Have I got that right? -fnerd quote me

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Re: Blasting Bidzos Blather
by fnerd＠smds.com 18 Jun '93

18 Jun '93

> Oh, here goes another Big Bad Corporation abusing our rights...! Well, are > there any Libertarians out there who will please speak up for the right of > Bidzos & co to earn a legal profit any way they see fit...? I'm a libertarian. I happen to be a type of libertarian who doesn't believe in patents. So I think nobody has a "right" to use government (or any force) to enforce their patents. BUT, many people believe patents are okay, and many feel they do have a right to enforce their patents. I think the RSADSI/PKP people are like this. It's a perfectly common belief. So except for the whole patent issue, (including the validity of their particular patents), I think they have a right to sell or not sell licenses to anyone they choose. BUT, to libertarians there's a big distinction between "You have a right to..." and "It's right for you to..." It's possible they're acting within their rights (with the exception noted above) and yet doing something wrong or evil. BUT, in this case I'm not sure whether what they're doing is particularly wrong, although I haven't seen a good case one way or the other. -fnerd quote me

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Inviso-Crypt(r)
by Kent Hastings 18 Jun '93

18 Jun '93

Inviso-Crypt(r) I'm proud to announce a new fuzzy-logic application that can access sub-digital biticles. These vitalistic fractional bits were never discovered before now because computer scientists are still clinging to a rigid notion of Aristotelian "A or not-A" on-off binary logic. It took a Fate magazine advertisement to inspire this scam, er- breakthrough. One of my beta testers was delighted to find his bank account dramatically compressed and his computer network rendered userless. Here is a sample of the program's output: !!! BEGIN INVISO-CRYPT(R) DATA BLOCK !!! !!! END INVISO-CRYPT DATA BLOCK !!! The preceding message may look like all spaces, but those 10 lines contain over 100 megabytes of encrypted biticles. Inviso-Crypt(r) works on graphic files, too. "+". That single character holds a 4-megabyte GIF image. Nothing works like, well, uh - nothing ... to the naked eye, of course. You've heard of Beethoven's "Emperor Concerto," this is nicknamed "The Emperor's New Code" around our data center. Our recent advance in applied cryptology works as described here or my name isn't Mr. Burns, oops, uh - Mr. Snrub, a dedicated computer scientist working at, uh - a lab very far away, on a chain of islands with affordable liability immunity and anonymous trust business structures. That'll do. This software not only does real time bit-slicing, it rolls virtual dice to generate random keys. Yes, it slices, it dices, and it will decrypt your DNA and cure cancer, colds, baldness, and all other ailments. This program is so important that my lobbyists are "passing bills" through Congress as you read this. (Ok Senator, I'm putting these bills on the trash dumpster, and when I get back, I expect them to be hauled away. Don't forget the free bar of soap to wash your hands of this whole affair. See, I DO support clean government.) Soon, Inviso-Crypt(r) will be the exclusive national standard. Why, my payroll expenses have been amazingly smaller since I printed paychecks using the Inviso-Cash(r) standard. Homer: "Hello - money, where are you?" "I like the way that Inviso-Crypt(r) works!" - Smithers.#000#

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Re: xor w/prbs
by collins＠newton.apple.com 18 Jun '93

18 Jun '93

While the pseudo-random bit sequence algorithm used in the Computer Shopper article is weak, it is important to note that the article is on the right track. However, a one time pad based on PRBS is only as secure as the PRBS itself. If the author did not state this, he was remiss. There *are* cryptographically strong pseudo-random bit generators. A one time pad based on a CSPRBS would be as secure as the underlying 'hard' problem. For example, Blum and Micali's paper "How to Generate Cryptographically Strong Sequences of Pseudo-Random Bits" (Nov. 84 SIAM), details a scheme based on the discrete log problem. Essentially, this system is based on selecting bits from successive exponentiations of a seed. If you could guess the next bit to be selected, without knowing the seed, you could reverse this into an algorithm to solve the discrete log problem. The Blum and Micali paper also references a paper by Shamir (which I have not read) called "On the generation of cryptographically strong pseudo-random sequences" 8th International Colloquium on Automata, Languages and Programming, Lecture Notes in Coputer Science, 62, Spring-Verlag, New York, 1981. The difference being that the Shamir scheme generates *numbers* while the Blum/Micali scheme generates *bits*. I try never to label anyone a moron until I am sure their stupidity is not just my failure to communicate. Scott Collins | "Few people realize what tremendous power | there is in one of these things." | -- Willy Wonka ...................................................................... Apple Computer, Inc. | phone: 408 862-0540(v), 974-6094(f) 1 Infinite Loop, MS 301-2C | AppleLink: SCOTTCOLLINS Cupertino, CA 95014 | internet: collins(a)newton.apple.com

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Re: fast des
by smb＠research.att.com 18 Jun '93

18 Jun '93

> Run your plaintext through compress first; remove the compress > header; then encrypt. Compression will screw up character frequencie s > (and use all eight bits) enough to make automated detection of a > successfully-broken encryption really darn hard. Especially if you > keep changing compression technology each message. Most encryption scheams use cypher block chaining or some other mechanism where a change in one block will affect every block to come after it, no? Given this, would inserting a block of random data at the begining of the datastream help? Probably not. The DES-crackers are already going to be looking at a couple of blocks, because in general, the cryptanalyst won't know the IV. But not knowing it only affects your ability to decrypt the very next block; you can still get the one after it. The decrypt equation for CBC mode is P[n] <- D(C[n]) xor C[n-1] That is, without knowing the IV -- C[0] -- you can't recover P[1]. But P[2] depends only on C[2] and C[1]. If P[1] is random garbage, you've actually made life a bit easier -- the block they can't recover isn't important.

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Re: Blasting Bidzos Blather
by George A. Gleason 18 Jun '93

18 Jun '93

Oh, here goes another Big Bad Corporation abusing our rights...! Well, are there any Libertarians out there who will please speak up for the right of Bidzos & co to earn a legal profit any way they see fit...? Or am I, the token leftist in the crowd, going to stick my neck out solo on this one...? Pardon my rhetoric, but I find it truly amazing how the much extolled rights of private property can suddenly become a non-issue when you consider you've found a bigger issue. Some of us feel that way about ecology. -gg

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re: fast des
by Jason Zions 18 Jun '93

18 Jun '93

>>Usually the limiting factor is examining the <ostensibly> decrypted data >>for statistically significant patterns indicating that you have the >>correct key. > >If you know that your plaintext is 7-bit ASCII, then you can reject if you >see too many 8th bits set. [ ... ] Hint for implementors: don't allow such >easy bit correlations in your plaintext. Run your plaintext through compress first; remove the compress header; then encrypt. Compression will screw up character frequencies (and use all eight bits) enough to make automated detection of a successfully-broken encryption really darn hard. Especially if you keep changing compression technology each message. Jazz

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Re: fast des
by wcs＠anchor.ho.att.com 18 Jun '93

18 Jun '93

Steve Bellovin refers to Hans Eberle's paper on a GAs-based 1Gb/s DES chip, which is available on gatekeeper.dec.com under the SRC directory. The search time of 16 days for $1M, aka 1 day for $30M (incl. support chips), is fairly similar to Peter Wayner's Content-Addressible-Memory approach, which would cost an estimated $30M for a 1 day search. (Average search time is about half as long as exhaustive searches.) To put this in a cost-per-solution context, if you amortize over 5 years, that's about 4000 solutions, so that's a bit under $10K per solution. It's more expensive than David Sternlight's $25/solution guess, but it's interestingly small - certainly worthwhile for occasional national security applications, or robbing electronic funds transfer networks, (at least for the $1M slower version), and it's in the ballpark of the rental rate for Congressmen :-) (the Abscam folks paid $50K to Senator Harrison Williams for some light work...) Since Skipjack uses an 80-bit key, the NSA or other rich organizations with access to it ought to be able to get similar performance in 24-48 years, assuming speed doubling continues at its 1-2 year rate. We'd be better off with something with a longer key, such as triple-DES. Bill Stewart

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Contempt of court
by Mike Godwin 18 Jun '93

18 Jun '93

Forwarded message:

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