known plain-text attacks

[Johan Wevers]

Atom 'Smasher' wrote:

>i'm wondering about the *asymmetric* algorithms. that's the part were one
>would have two pieces of information to launch an attack (if such an
>attack is feasible)... one would have a public-key and known plain-text
>(the session-key).

For the asymmetric algorithms the symmetric key is just data to be
encrypted; that this is a key for another encryption does not matter for
them. Your question is equivalent to the question if it's possible to
compute the secret key given the public key. The answer is yes, this is
possible, but it takes too much time to be of practical value.

-- 
ir. J.C.A. Wevers         //  Physics and science fiction site:
johanw at vulcan.xs4all.nl   //  http://www.xs4all.nl/~johanw/index.html
PGP/GPG public keys at http://www.xs4all.nl/~johanw/pgpkeys.html