Re: [PATCH] Delete cryptoloop

Pascal Brisset
2004-07-22T19:47:20Z

hpa@zytor.com (H. Peter Anvin) wrote in message
news:<2kMAw-rl-15@gated-at.bofh.it>...
> So does cryptoloop use a different IV for different blocks? The need
> for the IV to be secret is different for different ciphers, but for
> block ciphers the rule is that is must not repeat, and at least
> according to some people must not be trivially predictable. [...]

The IV is predictable in cryptoloop and in other implementations.
This causes specially crafted watermarks to be detectable through
the encryption [1]. Pretty bad, but whether this is really a
concern or not depends a lot on what you are encrypting.

-- Pascal

[1] Markku-Juhani Saarinen: Encrypted Watermarks; Security Vulnerabilities in Laptop Encryption (Security Forum Workshop 2004)