Re: Prime magnitude and keys...a ?

[Jim choate <ravage@bga.com>]

> What do you mean by "greater or lesser than the actual key"? If you mean 
> number of bits you can do a simply file size comparison, if you mean 
> binary numerical value a simple c program _should_ be able to handle that 
> without any trouble I think.... although maybe you would need to include 
> some of those 'big number' routines I keep hearing about... and you would 
> have to strip off any header info before computing.
> 
> Happy Hunting, -Chris.
> 
What I am looking at is a way to do binary searches in the key space w/ a 
function that would look at a test key and the result of running RSA on 
it and then tell me the relative magnitude between the real key and the
test key. 

What this means is that I could take a cypher-text and attempt a de-crypt
w/ some conveniently large number and then go up or down from there 
till I find it. The advantage of this approach is that it allows one to
search the key-space w/o having to test each and every possibility. This
would significantly(!) reduce the time to crack...