Forwarded From: "Jay D. Dyson" <jdysonat_private> Forwarded From: Frank Andrew Stevenson <frankat_private> Posted To: cryptographyat_private After over 1 year of preperation the keyblitz project realeased it's DES searching client on May 1st this year, the search was only allowed to run for 11 days before it faced a possible legal challenge: http://www.thoic.com/keyblitz/ The keyblitz search is not a academic DES challenge, but a real life 'malicious' attack on a deployed cryptographic system. The target of the search is management keys for the European D2-MAC / Eurocrypt sattelite scrambling system. Although the search had only been running for 11 days the team claimed to have recovered 2 DES keys already. This is made possible by exploiting a weakness in the Eurocrypt protocoll. TV signals are coded under the control of a single Operational key. However this key is continously being updated to the systems smart cards encrypted under as many as perhaps 2000 different managment keys. Recovering a single managment key will suffice to recover future operational keys. The modified DES search will encrypt the known operational (plaintext) key with a set of trial keys, and check every encryption against the list of 2000 ciphertexts. Such a lookup is much faster that 2000 trial encryptions, and can be done quickly using binary search or table lookups. The net result is that the complexity of recovering a single management key is 2^45 as opposed to 2^55 of recovering a single DES key. Subsequent operational keys can then be found by simple decryption, and published over the internet on such sites as http://www.d2mac.com frank - -- This sentence is unique in this respect; it can safely be attributed to my employer, Funcom productions. E3D2BCADBEF8C82F A5891D2B6730EA1B PGPencrypted mail preferred, finger for key There is no place like N59 50.558' E010 50.870'. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBNVhybOe1NzV7EsRFAQHkwQP8CG962QTqi+U9ML+3T1uflfJYipW6i3V/ R3keDS7htyl4b90RYzjeMspYobwexBESlJF7HI8BGpOXx6hGYfgKcgDDorbFz2eK LwhTDXgY8nDLB16yXO5hrIWbLm3UJ7ipzCWykbWesLRIIiNZu0t0kjMx2xiqUA/U Rmdn+b0rD5E= =Ygmx -----END PGP SIGNATURE----- -o- Subscribe: mail majordomoat_private with "subscribe isn". Today's ISN Sponsor: Repent Security Incorporated [www.repsec.com]
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