Re: make one symmetric key of two symmetric keys

No, no superencryption, a wonder how do combine two symmetric keys to
one, assume two 128 bits key K1 and K2, is it safe to do K3=K2 (XOR)
K1, or is it more safe to do K3 =H(K1) + H(K2), if 2 hashes equals 128
bits. Another question is, assume that K1 is broken by some adversary,
is it them safe to do K3=K2 (XOR) K1, or does the broken K1 give to
mush information about K3. Is it then safer to do K3 =H (K1) + H (K2)?
If hashing is better can you give me a appropriate hash function.

Regards
Ulf Reiman

Ludovic Joly skrev:

Sounds like you want to achieve superencryption some way. If so just
google this term. It's well documented and you'll find lots of useful
and interesting resources.

Kind regards
Ludovic Joly

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