[Cryptography] Are there other anonymous key exchange algorithms?

[Lars Luthman]

On Sat, 2014-05-17 at 14:29 +0200, Miroslav Kratochvil wrote: 
> Hello list,
> 
> so there has recently been a discussion about solving some previously
> unsolvable examples of discrete logarithm on slashdot [1] (not
> particularly harmful for cryptography though), which mostly made me to
> finally ask about this.
> 
> The big question:
> Is there any other anonymous key exchange algorithm than Diffie-Hellman?
> 
> Or any other good method (preferably post-quantum) that would allow
> perfect forward secrecy without D-H?

Any public key encryption algorithm can be used for key exchange, the
trivial generic method is to have each party generate a random bit
string, encrypt it to the other party's key, send it, receive the other
encrypted bit string, decrypt it, and compute the master secret as a
hash of the XOR of both bit strings. Forward secrecy simply means that
you generate a new keypair for every exchange.


--ll
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