cypher algorithm - which one?

David Picón Álvarez eleuteri@myrealbox.com
Sat Nov 2 17:33:01 2002


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Hi,

> It's a difficult question, because it's sort of an apples-and-oranges
> comparison.  It really depends on what you are using the key for.  a
> 1024bit DSA signing key is generally felt to be more or less as secure
> as the 160-bit hash that it uses.  If you make a bigger DSA (and this
> is technically possible, though GnuPG and PGP follow the spec and stop
> after 1024), you still have that 160-bit hash as your weak point.


Assuming a hash is well-defined and so on, isn't it roughly as strong as a
symmetric cipher of the same length? If so, I've read repeatedly that a
symmetric 128 bit cipher is very likely stronger than a 2048 asymmetric one.

--David.



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