RSA Versus DSA and EL GAMAL

[David Shaw]

On Mar 13, 2011, at 11:21 PM, Jonathan Ely wrote:

> I apologise in advance if this is a stupid question to ask now or if
> people already asked it before I stepped on the scene, but which
> algorithm is more secure: DSA and EL GAMAL or RSA? I know the latter has
> undergone a ridiculous amount of scrutiny and is immensely popular. I
> also know it generates longer keys.
> 
> I have a 4096 RSA key but really never found the answer whilst searching
> beforehand which one to choose. I know 4096 is much better than 2048, so
> I can not figure out why Enigmail defaults to a 2048 instead of 4096 but
> whatever. I am not concerned about speed; I will gladly sacrifice speed
> for security any day. As always, thanks for the future lessons.

This is a very frequently asked question on this list.  You might hit Google and see some of the previous discussions.  Basically though, the argument between RSA and Elgamal is like comparing a 9999-foot wall vs a 10000-foot wall (and I'm not saying which is the 9999 and which is the 10000).  Does the difference really matter, as long as you can't climb over either one?

The short answer: use RSA.  It's the default for various little fiddly operational reasons, none of which are relevant to the question of "which is more secure".

David