Welcome to Jon's
|Cryptography & privacy are very important in
today's world. The ability to have private electronic
conversations in an increasingly monitored world is
essential, although the government would like you to
A good place to find links to information about cryptography online is the Yahoo! Security & Encryption page.
Some thoughts on how hard it is to brute force a 128-bit key, which is what PGP uses:
Is brute-forcing a 128 bit key feasible right now? Will it ever be feasible?
I can say absolutely not to the first question. The second one is of course a little harder, but I think it will be quite a long time before we get to the point where we can harness that kind of computing power. Here's why:
To brute force a 128 bit key, you need to (on average) try 2127 keys. How big a number is that?
Well, it's trivial to brute-force a 40 bit key. It's relatively easy to brute force a standard DES key, which is 56 bits. 64 bits is getting harder...
As you can see, 2127 is a pretty big number. How long would it take to crack a key that size?
Well, let's say for the sake of argument you had a chip that could crack a 64 bit key in one second. That means it can try 263 keys in one second. A system that could do that right now would cost in the millions of dollars (maybe even hundreds of millions). Now, lets take a big leap. Let's say you had one billion (1,000,000,000) of these chips. Could you crack a 128 bit key?
Sure, but it would take you over 550 years to crack a single key...