Key to breaking Nazi code was in the patent office
http://www.telegraph.co.uk/et?ac=004782403739693pg=/et/01/4/20/ncyph20.html By Michael Smith Friday 20 April 2001 BRITAIN'S wartime codebreakers could have cracked the German Enigma cipher machine much earlier if they had followed a diagram for the commercial version lodged with the British Patent Office in the mid-1920s, documents released to the Public Record Office show. But the codebreakers did not believe that the German army would have been so stupid as to use the same simple wiring system as the widely available commercial machine for their military equivalents. The Code and Cypher School, commonly known by its wartime home at Bletchley Park, was fully aware of how the commercial machine worked in the mid-1920s. Chiffriermaschinen Aktiengesellschaft, the German company that manufactured it, had offered the British Government commercial Enigma machines at a price of $190 each in June 1924. Britain declined to take up the offer, waiting for the Germans to register it with the British Patent Office. Then they obtained the description of how it worked from the patent officials, including detailed plans of the make-up of the commercial machine.The files show that, contrary to what had previously been thought, British codebreakers were working on the Enigma machine during the 1920s and 1930s. But they did not manage to break the military variant until early 1940 after gaining vital help from the Poles. The Enigma machine looked like a typewriter. Pressing the keys sent an electrical impulse through a series of circuits wired through rotors that moved with each tap of the key, constantly varying the cipher. British codebreakers had made a good deal of progress in breaking the military version but were held up because they could not work out the order in which the typewriter keys were wired into the internal circuits. The Germans weren't idiots, said Peter Twinn, one of those who broke Enigma. When they had a perfect opportunity to introduce a safeguard to their machine by jumbling it up, that would be a sensible thing to do. It was not until July 1939, when they met their Polish equivalents who had broken early versions of the machine, that they found out that it was wired alphabetically, A to the first contact, B to the second contact and so on. This was the same as in the diagram attached to the patent application but was so obvious that the codebreakers never even considered it as a possibility. Six months later, codebreakers made their first break into Enigma, something they could have done far earlier if they had only tried the alphabetical system in the patent application.It was such an obvious thing to do, really a silly thing to do, that nobody ever thought it worthwhile trying it, said Mr Twinn. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Requesting feedback on patched RC4-variant
In general, if you're not an expert (:), it's worth not messing with the core parts of algorithms to prevent an attack when you don't undertand the attack. I do fully understand how both RC4 and the attack work. [I'm not so sure about that. --PM] RC4 has two basic rules for using it securely - Use long enough keys. - Never EVER reuse a key. I did those already, I was very well aware that reusing an RC4 key is a no-no, I even explained the need for this to other people. The basic things wrong with the use of RC4 in several broken commercial environments (e.g. 802.11 WEP, MS PPTP) include snip Too short key length wasn't the only problem in WEP: Another problem arose from the fact that when you toggle a single bit in the ciphertext, that *same* bit is toggled in the plaintext. [That's not an RC4 feature -- that's a feature of any stream cipher. However, in general, any time you use a cipher in a communications protocol, you want a MAC as well, even if you are using a block cipher in CBC. --PM] Therefore, if the contents of part of the ciphertext is known, that part could be modified. WEP has integrity checking to protect against this, however they did this in a flawed way. (the propogation of a bit toggle can be tracked through the CRC algorithm to determine which bits of the CRC should be toggled to make sure the change will not be detected) in general, I'm not comfortable with this bit-toggle property, but RB is too sucky to implement a decent algorithm. Well, I'm working on getting cryptlib working on MacOS anyway, and then turn it into an RB plugin, and all my problems will be solved :-) Matthijs van Duin - PGP Key: 0xB6205CCB finger:[EMAIL PROTECTED] - - FP: D73C 9EE3 5F6B E5D5 8E19 2CBE 4648 8C3E B620 5CCB - - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: NTT offering free licenses for algorithms (incl. Camellia)
Kristen Tsolis wrote: According to Nikkan Kogyo News, NTT is offering four patented algorithms under royalty-free license for limited purposes. These algorithms include Camellia, EPOC, PSEC, and ESIGN. http://news.yahoo.co.jp/headlines/nkn/010418/nkn/08100_nkn13.html NTT made this announcement on the same day as the last CRYPTREC meeting. The CRYPTREC project was initiated by Japan's Information-technology Promotion Agency (IPA). The goal of CRYPTREC is to define standard cryptographic algorithms for use within the Japanese government. http://www.ipa.go.jp/security/enc/CRYPTREC/index-e.html There was extensive discussion on the inclusion of Camellia in TLS ciphersuites recently - I can't remember the outcome, though, sorry. Cheers, Ben. -- http://www.apache-ssl.org/ben.html There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit. - Robert Woodruff ApacheCon 2001! http://ApacheCon.com/ - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Another shining example of Microsoft security.
On Fri, Apr 20, 2001 at 05:44:55PM -0400, vertigo wrote: On Fri, 20 Apr 2001, Enzo Michelangeli wrote: Besides, the fact that many users don't check the validity of the certs presented by the other side is a disgrace, and should not be encouraged by distributing broken software. It certainly should not be encouraged. The fact remains that informed users are rare. The algorithms are strong, but the infrastructure is cream of wheat. Microsoft, if this is true, (I use Pine and there isn't a copy of Outlook anywhere in sight) has done an injustice not only to the user but, more importantly, to the infrastructure. The Pine SSL patches also don't do any validity checking of certificates, AFAIK. Kris PGP signature
Re: Another shining example of Microsoft security.
On Sat, Apr 21, 2001 at 05:11:21AM -0400, vertigo wrote: Pine has SSL patches? :) It's plain old pine within an SSH session for me. Yeah - they implement IMAP-over-SSL, with the aforementioned limitation. The Pine SSL patches also don't do any validity checking of certificates, AFAIK. Kris PGP signature
