Cryptography-Digest Digest #776
Cryptography-Digest Digest #776, Volume #13 Fri, 2 Mar 01 05:13:00 EST Contents: Re: The AES draft FIPS is out!!! (Paul Crowley) Re: how long can one Arcfour key be used?? (Paul Crowley) Re: Rijndael S-box inverse (Paul Crowley) Re: super-stong crypto, straw man phase 2 (wtshaw) New web site ("Greg Ofiesh") Re: RC4 like stream cipher ("Scott Fluhrer") Re: "RSA vs. One-time-pad" or "the perfect enryption" (Steve Meyer) Re: The AES draft FIPS is out!!! ("Brian Gladman") Re: "RSA vs. One-time-pad" or "the perfect enryption" (Nicol So) Re: "RSA vs. One-time-pad" or "the perfect enryption" (Nicol So) Re: super-stong crypto, straw man phase 2 (Nicol So) Re: Urgent DES Cipher source code ! (Frank Gerlach) How good is the KeeLoq algorithm? (Søren A.Møller) Re: Keystoke recorder (Frank Gerlach) ARCFOUR and Latin Squares ("r.e.s.") Re: => FBI easily cracks encryption ...? (Frank Gerlach) Re: HPRNG (Frank Gerlach) Re: How good is the KeeLoq algorithm? (Frank Gerlach) Subject: Re: The AES draft FIPS is out!!! From: Paul Crowley <[EMAIL PROTECTED]> Date: Fri, 02 Mar 2001 06:32:58 GMT "Tom St Denis" <[EMAIL PROTECTED]> writes: > "Volker Hetzer" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED]... > > Check http://csrc.nist.gov/encryption/aes/ . > > Greetings! > > Volker > > A postscript is available at > > http://tomstdenis.home.dhs.org/nist_aes.ps.gz ...since the original is available only in Microsoft Word format. Thanks Tom! -- __ \/ o\ [EMAIL PROTECTED] /\__/ http://www.cluefactory.org.uk/paul/ -- Subject: Re: how long can one Arcfour key be used?? From: Paul Crowley <[EMAIL PROTECTED]> Date: Fri, 02 Mar 2001 06:32:57 GMT "Tom St Denis" <[EMAIL PROTECTED]> writes: > "Scott Fluhrer" <[EMAIL PROTECTED]> wrote in message > news:97knf5$66h$[EMAIL PROTECTED]... > > > Agreed. Of course putting ASCII into RC4 directly is a "dumb" idea. It > > > severely cripples the key generation process. > > > > Do you have a reference to that? [snip] > No, I don't have an exact attack but I feel better using a hash on ascii > passphrases first. It concentrates the entropy better (in theory) and > avoids the potential weakness. Interestingly, CipherSaber uses the fact that passphrases are ASCII to avoid the RC4 weak keys. I'd say the RC4 key schedule is slightly inadequate no matter how your key bytes are drawn, but that if you discard 256 bytes of output after scheduling as is often recommended, you should be OK with ASCII, binary, or any string with sufficiently high entropy. -- __ \/ o\ [EMAIL PROTECTED] /\__/ http://www.cluefactory.org.uk/paul/ -- Subject: Re: Rijndael S-box inverse From: Paul Crowley <[EMAIL PROTECTED]> Date: Fri, 02 Mar 2001 06:32:58 GMT I worked out the shifts needed to do the inverse affine transformation in Rijndael with a simple exhaustive search. Remember to do this *before* applying the self-inverse S-box, rather than after as with the forward direction :-) This definition is in Python because I've been learning it, but Python looks so much like pseudocode that you're unlikely to have trouble decoding it if you're familiar with C-style operators like | for "or", ^ for "xor" and "<<" for "shift left". def rot1(t): return ((t << 1) | (t >> 7)) & 0xFF affine_box = [None] * 256 for i in range(0,256): ri = rot1(i) ai = i ^ ri ri = rot1(ri) ai = ai ^ ri ri = rot1(ri) ai = ai ^ ri ri = rot1(ri) affine_box[i] = ai ^ ri ^ 0x63 inv_affine = [None] * 256 for i in range(0,256): ri = rot1(i) ai = ri ri = rot1(ri) ri = rot1(ri) ai = ai ^ ri ri = rot1(ri) ri = rot1(ri) ri = rot1(ri) inv_affine[i] = ai ^ ri ^ 0x5 -- __ \/ o\ [EMAIL PROTECTED] /\__/ http://www.cluefactory.org.uk/paul/ -- From: [EMAIL PROTECTED] (wtshaw) Subject: Re: super-stong crypto, straw man phase 2 Date: Fri, 02 Mar 2001 00:23:29 -0600 In article <[EMAIL PROTECTED]>, "Douglas A. Gwyn" <[EMAIL PROTECTED]> wrote: > William Hugh Murray wrote: > > "Douglas A. Gwyn" wrote: > > > William Hugh Murray wrote: > > > > In any case, most of us do not worry about keeping secrets from > > > > nation states for a long time. > > > Well, you should! > > I admit that I do like to confound authority. > > Another point is that "super strong crypto" ought to mean that > *nobody* can c
Cryptography-Digest Digest #776
Cryptography-Digest Digest #776, Volume #12 Tue, 26 Sep 00 04:13:00 EDT Contents: Re: A Different Kind of Quantum Computer (SCOTT19U.ZIP_GUY) Re: Tying Up Loose Ends - Correction (SCOTT19U.ZIP_GUY) Re: Question on biases in random numbers & decompression (SCOTT19U.ZIP_GUY) Re: NTRU question (actually truncated modular polynomial question) (Scott Contini) Re: Tying Up Loose Ends - Correction (Guy Macon) Re: Encryption Project ("kihdip") Test for weak keys in 3DES ("kihdip") Re: On block encrpytion processing with intermediate permutations (Bryan Olson) From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY) Subject: Re: A Different Kind of Quantum Computer Date: 26 Sep 2000 03:46:00 GMT [EMAIL PROTECTED] (John Savard) wrote in <[EMAIL PROTECTED]>: >On Mon, 25 Sep 2000 15:37:42 -0700, "A. Melon" ><[EMAIL PROTECTED]> almost wrote, in part: > >>Quantum computers can only solve problems in BQP, which is not thought >>to include NP-complete problems. Now there is a new type of quantum >>computer being proposed: > >>http://xxx.lanl.gov/abs/quant-ph/9910073 > >>The paper claims this could solve NP-complete and sharp-P-complete >>problems. > >>No, this isnt the End Of Cryptography As We Know It (EOCAWKI). Even if >>the claims are true, it may be impossible to actually build. Even if >>it is possible to build, it will be easy to make ciphers that defeat >>it. > >>For example, make a random, public, invertible, 27x27 sbox, and >>distribute it on CD-ROM. Encrypt a block by applying AES, then passing >>it through the sbox (in groups of 27 bits), then applying AES again. >>The sbox is only 432MB, so it is easy to distribute. > >Oh, dear. I have visions Scott27u now. > Well actually I know I did 4 8 16 and then 19. I am quite happy with prime numbers for the future ones so lets wait a few years till floppies commonly hold several gigs and leap to scott29u >>The quantum computer >>would need millions of qbits to crack it. > >I wonder. There might be a meet-in-the-middle attack. Because the >quantum computer's copy of the CD-ROM would *not* have to be in qbits, >since the CD-ROM is fixed and public; the number of qbits only has to >be the length of the secret key. But the non-qbit size of the problem >might still create problems in avoiding decoherence or something. > Your correct John you have been reading more than Enigma that is what I haver read also. Most systems to be modeled you need only enough qbits to match the key length. But since most still don't believe quantum computers exist. You may be wasting your time telling those in this group. David A. Scott -- SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE http://www.jim.com/jamesd/Kong/scott19u.zip Scott famous encryption website **now all allowed** http://members.xoom.com/ecil/index.htm Scott LATEST UPDATED source for scott*u.zip http://radiusnet.net/crypto/ then look for sub directory scott after pressing CRYPTO Scott famous Compression Page http://members.xoom.com/ecil/compress.htm **NOTE EMAIL address is for SPAMERS*** I leave you with this final thought from President Bill Clinton: -- From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY) Subject: Re: Tying Up Loose Ends - Correction Date: 26 Sep 2000 04:00:43 GMT [EMAIL PROTECTED] (Tim Tyler) wrote in <[EMAIL PROTECTED]>: >Mok-Kong Shen <[EMAIL PROTECTED]> wrote: > > >: BTW, could you answer my question of whether Scott's >: 1-1 scheme can deal with arbitrary boundaries, since >: you are apparently fairly familiar with that? > >I believe David found that Matt Timmerman's scheme could be simply >adapted to allow for abritrary block boundaries. IIRC David advised >Matt of this, and Matt implemented it. I might be making all this up, >though ;-| > >Anyway, on http://members.nbci.com/ecil/compres5.htm David has code that >bijectively goes to and from Matt's finitely odd files - i.e. binary >strings that end with a 1 followed by an infinite zero tail. > >The code... >Converts to/from files made of any number of bytes; >Converts to/from even byte length files; >Converts to/from odd byte length files; >Converts to/from 8 bytes multiple file. > >I don't know if David's used other types of granularity. I figure he >knows how to do it if he wants to. > >His original compression programs only worked with byte-oriented files. >I don't know if this has changed since I last looked at them. > >You could probably chain their output through the "finitely odd" >convertors, if you wanted other types of granularity.
Cryptography-Digest Digest #776
Cryptography-Digest Digest #776, Volume #11 Mon, 15 May 00 08:13:00 EDT Contents: Re: S-BOX Construction Tutorial? (Mok-Kong Shen) Re: Definition of "Broken" Cipher (Mok-Kong Shen) Re: S-BOX Construction Tutorial? (Terry Ritter) Re: Notes on the "Vortex" block cipher (Terry Ritter) Re: How does one test an encryption algorithm? (Runu Knips) Re: Using TEA in one-way hash function ("adam pridmore") Re: Notes on the "Vortex" block cipher (Tom St Denis) Re: S-BOX Construction Tutorial? (Tom St Denis) Re: Encryption of graphics by transposition (Tom St Denis) Q: Searching for multiparty authentication protocols (=?iso-8859-1?Q?Tom=E1s?= Perlines Hormann) Re: Unbreakable encryption. (Paul Waserbrot) Re: Unbreakable encryption. (Runu Knips) Re: AES Comment: the Hitachi patent (Runu Knips) Re: Q: Searching for multiparty authentication protocols (Tom St Denis) Re: Unbreakable encryption. (Mok-Kong Shen) Re: Notes on the "Vortex" block cipher (Runu Knips) Re: Unbreakable encryption. (Mok-Kong Shen) Re: Unbreakable encryption. (Tom St Denis) Re: Unbreakable encryption. (Tom St Denis) From: Mok-Kong Shen <[EMAIL PROTECTED]> Subject: Re: S-BOX Construction Tutorial? Date: Mon, 15 May 2000 08:07:31 +0200 Scott Fluhrer wrote: > Mok-Kong Shen <[EMAIL PROTECTED]> wrote: > Another cost of having key dependant sboxes is key agility. If you either > are using a different key to encrypt each different message, or if you use > so many different keys that it is impractical to save the expanded key > schedules, then how long it takes to set up for a particular key is > important. And, having to compute what the S-boxes look like each time is a > serious hit. > > Although, I must say that Twofish took an interesting approach. Perhaps > other cipher designers should examine it. Computing the random S-boxes can certainly be a substantial cost that is to be counted on the negative side of that approach. On the other hand, if one chooses to use fixed S-boxes, then I am of the humble opinion that one should have different ones in different rounds. M. K. Shen -- From: Mok-Kong Shen <[EMAIL PROTECTED]> Subject: Re: Definition of "Broken" Cipher Date: Mon, 15 May 2000 08:29:46 +0200 Tom St Denis wrote: > It's quite simple. You don't say your car is broken because of a dent > in the fender right? It depends. Gates might change his car. On the other hand, there is a good business in Europe buying cars that nobody wants to have and selling these to some developing countries. Whether a cipher is good to use depends on the application and your (more or less subjective) judgement, I believe. Single DES is e.g. yet good enough for a fairly wide range of applications. M. K. Shen -- From: [EMAIL PROTECTED] (Terry Ritter) Subject: Re: S-BOX Construction Tutorial? Date: Mon, 15 May 2000 06:31:38 GMT On Mon, 15 May 2000 04:31:57 GMT, in <[EMAIL PROTECTED]>, in sci.crypt [EMAIL PROTECTED] (John Savard) wrote: >On Mon, 15 May 2000 02:09:39 GMT, [EMAIL PROTECTED] (Terry Ritter) wrote, >in part: > >>What are you talking about? > >>Every enciphering has some key. Any opponent might just try that key >>at random. Does that make the cipher weak? Does that make the >>keyspace non-flat? > >>Similarly, if we construct S-boxes such that they are a "random" >>selection from among the universe of such S-boxes, does the fact that >>one of these is the "identity transformation," others are close, and >>many are somewhat linear make any difference at all (assuming the >>universe of possible S-boxes is "large enough")? > >Actually, the fact that some S-boxes are close to being linear, while >others are not, does mean that some keys are "better" than others in a >way that is not applicable to a cipher like DES. (Although DES does >have weak keys for another reason.) Sure. And if we consider opponents who always start brute force keysearching with the same key, then our use of that key will be weak. But we don't know which key the opponents will start with, and we are forced to use *some* key. Nevertheless, one of the keys in the universe of all possible keys -- in fact whole groups that the opponents will search -- will be "weak." In that sense cipher keyspaces are *always* non-flat, and we accept that. I think it would make sense to object to a probabilistic design if provably secure designs existed. But since they do not, I think we find that any alternative to a probabilistic design is worse. >This has been used as a reason - or as an excuse - for not using >key-dependent
Cryptography-Digest Digest #776
Cryptography-Digest Digest #776, Volume #10 Tue, 21 Dec 99 03:13:01 EST Contents: Re: DES as pseudo random number generator (UBCHI2) Re: An attack on the WTLS SHA_XOR_40 MAC algorithm (Markku-Juhani O. Saarinen) How do you know if you found a key? (Greg) Re: RST discovers defective crypto in Netscape mail password saver (Ken Lamquist) Re: AES and MATTS COMPRESSION ("Matt Timmermans") Re: Q: transcendental pad crypto ("dls2") Re: Q: transcendental pad crypto ("Trevor Jackson, III") Re: How do you know if you found a key? (David A Molnar) WEBPAGE UPDATED (SCOTT19U.ZIP_GUY) Re: compression & encryption (Ken Lamquist) Re: Keystrokes monitored/encryption useless (Guy Macon) firmware encryption? ([EMAIL PROTECTED]) Re: US Patent Office: How Stupid? Look Here... (Anthony Stephen Szopa) From: [EMAIL PROTECTED] (UBCHI2) Subject: Re: DES as pseudo random number generator Date: 21 Dec 1999 02:11:00 GMT It's not a bad idea at all. Just run your fingers randomly over the keyboard. Then encrypt with des. Then you pull out the numbers out of the encrypted text and use those as a one time pad. Neat Idea -- From: Markku-Juhani O. Saarinen <[EMAIL PROTECTED]> Subject: Re: An attack on the WTLS SHA_XOR_40 MAC algorithm Date: 21 Dec 1999 02:18:15 GMT David Hopwood <[EMAIL PROTECTED]> wrote: > David Wagner wrote: > > Good catch. Yeah, I agree: the so-called WTLS 'XOR MAC' is seriously > > flawed, and definitely should be eliminated with all possible haste. > > Submitting your result to WAP might be useful, to keep them honest. > I have done; I'll also point them to Saarinen's paper and outline your > repeated ciphertext attack. The WAP security group is aware of the results presented in my paper [1]. I have received the usual telecom-industry "doesn't work in practice" type of note regarding the results presented in my paper :-) > Has anyone checked whether the elliptic curves that do not have seeds given > for them are of any special form, BTW? They appear to be ok as far as I can tell. My guess that they were actually computed by Certicom (Certicom is selling a WTLS toolkit). I am currently updating and expanding the original paper [1]. Now that WAP and WTLS implementations are becoming available (Nokia, Siemens, Microsoft / Benefon, etc.) the issue of security bugs resulting from implementation detail is an interesting one.. I hope that I can get some funding for that line of research. - mj Markku-Juhani Saarinen <[EMAIL PROTECTED]> University of Jyväskylä, Finland [1] Markku-Juhani Saarinen, "Attacks Against the WAP WTLS Protocol," Secure Information Networks: Communications and Multimedia Security '99, Kluwer Academic Publishers, Boston, 1999, pp. 209--215 -- From: Greg <[EMAIL PROTECTED]> Subject: How do you know if you found a key? Date: Tue, 21 Dec 1999 04:15:08 GMT If you take random data, and you encrypt it with DES, then you search for the key using any and all known attacks, how do you know when you found the right key? -- The only vote that you waste is the one you never wanted to make. RICO- we were told it was a necessary surrender of our civil liberties. Asset Forfeiture- the latest inevitable result of RICO. http://www.ciphermax.com/book Sent via Deja.com http://www.deja.com/ Before you buy. -- From: [EMAIL PROTECTED] (Ken Lamquist) Subject: Re: RST discovers defective crypto in Netscape mail password saver Date: 21 Dec 1999 04:32:52 GMT Gary McGraw writes that "the encryption algorithm used by Netscape to scramble [E-mail] passwords is exceptionally weak." Encryption normally refers to encoding data in such a way that it is computationally infeasible to decode the data unless you know a secret key. Netscape does not do this with E-mail passwords. It does use a form of security through obscurity: the way that E-mail passwords are stored on disk is not documented. If security through obscurity worked perfectly in this case, it would mean that people would only be able to use the E-mail password by running netscape. Accessing E-mail using the password would still be trivial. Actually getting the password would be harder. Allowing for the inevitable MS Windows crash, it might take a pair of knowledgeable people a few hours to run netscape and capture the E-mail password it sends out. "Security through obscurity" is insecure, so McGraw's report that it took a pair of people eight hours to figure out how netscape stores E-mail passwords on disk is no big surprise. Since this is longer than the expected time to obtain the password just by running the program, it appears that in this case, secu
Cryptography-Digest Digest #776
Cryptography-Digest Digest #776, Volume #9 Fri, 25 Jun 99 17:13:03 EDT Contents: Re: Kryptos article (Jim Gillogly) Re: Why Elliptic Curve Cryptosystem is stronger with shorter key length? (DJohn37050) Re: one time pad (AllanW) Re: Bytes of "truly random" data for PRNG seed. (Terry Ritter) Re: RC4 Susectability ([EMAIL PROTECTED]) Re: DES-NULL attack ([EMAIL PROTECTED]) sha-1 C/C++ source code ([EMAIL PROTECTED]) Re: one time pad (AllanW) Re: Tough crypt question: how to break AT&T's monopoly??? ([EMAIL PROTECTED]) How does 3DES work? ([EMAIL PROTECTED]) Re: Converting arbitrary bit sequences into plain English texts (wtshaw) Re: Kryptos article (Jim Gillogly) Re: Bytes of "truly random" data for PRNG seed. (David A Molnar) Re: "Breaking" a cipher ([EMAIL PROTECTED]) Re: one time pad (John Myre) Re: Converting arbitrary bit sequences into plain English texts (wtshaw) Re: DES-NULL attack ([EMAIL PROTECTED]) Re: Converting arbitrary bit sequences into plain English texts (wtshaw) From: Jim Gillogly <[EMAIL PROTECTED]> Subject: Re: Kryptos article Date: Fri, 25 Jun 1999 12:16:32 -0700 Lincoln Yeoh wrote: > http://www.odci.gov/cia/information/tour/krypt.html > > Is that a hole on the lower right? And is that where we're supposed to dig > or look inside? It's a pool of water. I suspect if you stand a bit closer it would reflect the Vigenere table that's cut through the copper panels on the right; we're seeing them reversed, so presumably the pool will straighten them out for us. Is there another pool on the concave side of the cipher panels? -- Jim Gillogly 2 Afterlithe S.R. 1999, 19:14 12.19.6.5.10, 1 Oc 18 Zotz, Second Lord of Night -- From: [EMAIL PROTECTED] (DJohn37050) Subject: Re: Why Elliptic Curve Cryptosystem is stronger with shorter key length? Date: 25 Jun 1999 19:05:12 GMT Here is an advantage of ECC over other methods, the domain parameters are public, so one can use a Koblitz curve with a random curve as a backup. Note that this may entail NO change to the key generation code, if it allows selection of domain parameters. So one can get the benefits of Koblitz today, and if someone somehow finds out they are weaker than now thought, can switch to a random curve. Don Johnson -- From: AllanW <[EMAIL PROTECTED]> Subject: Re: one time pad Date: Fri, 25 Jun 1999 18:35:43 GMT [EMAIL PROTECTED] (Terry Ritter) wrote: > Were it possible to tell whether sequence s + '0' was more > random than s + '1', we could produce the one sequence which > was most random. But everybody would know that sequence so > it would be useless for cryptography. Heh heh, I like that. It's kind of like, "Give me a list of all well-known patterns, and then find the one that is least well-known!" The answer depends on the quality of the first list. > The whole point of crypto random is the hope that it is > not possible to know what the sequence will be. Right. Common RNG tests wouldn't be of any use, if they didn't check for known problems that make the next character in a sequence too easy to guess. For instance, we use frequency graphs to prove that each possible output byte is generated approximately the correct number of times. If we found that the byte value '0' was output only half as often as the odds predict it should be, we would call that a weakness because an attacker would rarely guess 0. -- [EMAIL PROTECTED] is a "Spam Magnet," never read. Please reply in newsgroups only, sorry. Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't. -- From: [EMAIL PROTECTED] (Terry Ritter) Subject: Re: Bytes of "truly random" data for PRNG seed. Date: Fri, 25 Jun 1999 18:38:20 GMT On Fri, 25 Jun 1999 12:49:24 GMT, in <[EMAIL PROTECTED]>, in sci.crypt "Douglas A. Gwyn" <[EMAIL PROTECTED]> wrote: >fungus wrote: >> The Blum Blum Shub I mentioned earlier is supposed to be "provably >> good" but I have to confess I don't know much about the algorithm >> or how the proof works. > >It's just iterated squaring (starting with a random seed) modulo a >product of two large primes (each of which is congruent to 3 mod 4). >The claim that BBS is "cryptographically strong" is based on the >difficulty of factoring, which of course is a field that has seen >rapid progress.. Actually, there is more to a real BB&S system. See: 20. Blum, L., M. Blum and M. Shub. 1983. Comparison of Two Pseudo-Random Number Generators. Advances in Cryptology: CRYPTO '82 Proceedings. Plenum Press: New York. 61