this may also interest you (and if you can find an archive of the cryptography list, the followups which discuss the report and particularly the use of nonstandard key exchange).
Begin forwarded message: From: "Steven M. Bellovin" <[EMAIL PROTECTED]> Date: October 23, 2005 9:48:37 AM EDT To: [email protected] Subject: Skype security evaluation Skype has released an external security evaluation of its product; you can find it at http://www.skype.com/security/files/2005-031%20security %20evaluation.pdf (Skype was also clueful enough to publish the PGP signature of the report, an excellent touch -- see http://www.skype.com/security/files/2005-031%20security% 20evaluation.pdf.sig) The author of the report, Tom Berson, has been in this business for many years; I have a great deal of respect for him. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb On Wed, Dec 28, 2005 at 08:02:12PM +0800, ½ÏþÁÖ wrote: > HI: > i have recently read the paper <Skype uncovered>,and have some > questions.In the part of UDP packet deciphering,the writer had mentioned > that "The RC4 key is generated using src/dst IP plus packet ID",and in the > figure the writer showed that we could use the src/dst IP plus packet ID to > generate the crc32,but in the former page,there had alread been a > crc32,so,where did it come from,and how should do to generate the correct > crc32. Besides, for the src ip,if the client was behind a NAT,its src ip > would be modified by the router when the packet pass out the NAT,and the > receiver would see another src ip,so how could it generate the right rc4 > key? > Finally,can somebody show me the deciphered data of the example,i wonde > if mine is right or wrong. > > expecting for your reply. > > Sincerely, > Jiangxiao > _______________________________________________ > Full-Disclosure - We believe in it. > Charter: http://lists.grok.org.uk/full-disclosure-charter.html > Hosted and sponsored by Secunia - http://secunia.com/ _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
