Re: IBM press release - encryption and authentication

[Ben Laurie]

David Wagner wrote:
> 
> Enzo Michelangeli wrote:
> >OpenPGP tries to detect such "wrong key" situations for
> >symmetrically-encrypted packets in a pretty simplistic way, [...]
> >   The repetition of 16 bits in the 80 bits of random data prefixed to
> >   the message allows the receiver to immediately check whether the
> >   session key is incorrect.
> 
> This does not provide message integrity or message authentication.
> It provides a much weaker property: If you've decrypted with the wrong
> key, this will let you detect that fact.

Padding also does that, of course.

Cheers,

Ben.

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