Re: [karp] FW: Stephen Farrell's Discuss on draft-ietf-karp-design-guide-04: (with DISCUSS and COMMENT)

[Stephen Kent <[e-mail]>]

>
>NEW
>Most importantly it provides fresh traffic keying material for each 
>session, thus helping to prevent inter-connection replay attacks. 
>Any fixed keystream output, generated from the same key and index 
>should only be used to encrypt once. Re-using such keystream 
>(jokingly called a 'two-time pad' system by cryptographers), can 
>seriously compromise security. The NSA's VENONA project [VENONA] 
>provides a historical example of such a compromise. Usually routing 
>protocols dont require encryption, however, if they do then using a 
>KMP avoids the two-time pad problem since packets from different 
>sessions are encrypted using distinct IVs, or, with distinct session 
>keys or both distinct IVs and session keys.

This text is better. But, since we have no established requirement 
for encryption for these protocols, it's also needlessly chatty, with 
about
90% of the text focusing on an encryption-based rationale. I suggest deleting
everything after the first sentence.

Steve