[Cryptography] Entropy Needed for SSH Keys?

[Sidney Markowitz]

Kent Borg wrote on 23/05/16 1:18 PM:
> Looks to me like it read 256-bits. I would have expected it would have 
> read more, just to waste if nothing else.
> 
> No where near using up 4096-bits (if "using up" even is real). Maybe do 
> both DSA and RSA? It still would only "use" 1/8 of a 4096-bit pool.

There is a difference between checking every one of the 2^256 4096 bit numbers
that could have been generated from that 256 bits of entropy and going through
all the calculations needed to factor a 4096 bit number. However both will
take you more time and resources than you have.

Both take much longer than factoring a 256 bit RSA key. Which is why 256 bits
is enough entropy to generate the key but the key has to be 4096 bits.