Re:Very Basic Intro to Elliptic Curve Cryptography
by shaftway on Wednesday July 22, 2020 @05:27PM
(#23921806)
> No, because usually the private key is around 256 bits, so you need to compute 2^255 hops on average to find the key.
So if my key is 255 bits long, then don't I need to do the 255 2^255 hops anyway to actually decrypt something? And in running 2^255 hops, wouldn't I have also cracked the key if it was any number less than that?
> bigger keys also result in longer encryption/decryption times.
So, there's a reasonable upper bound for the key length? Does that mean 256 bits aren't reasonable, and wouldn't this reasonable upper bound be more brute forceable?
Re:Very Basic Intro to Elliptic Curve Cryptography
by curyous on Wednesday July 22, 2020 @07:26PM
(#23922666)
You don't need to do that many hops when using your own key, because you can double it repeatedly. ie instead of adding 1 256 times to get 256, you just double it 8 times.
So if my key is 255 bits long, then don't I need to do the 255 2^255 hops anyway to actually decrypt something? And in running 2^255 hops, wouldn't I have also cracked the key if it was any number less than that?
> bigger keys also result in longer encryption/decryption times.
So, there's a reasonable upper bound for the key length? Does that mean 256 bits aren't reasonable, and wouldn't this reasonable upper bound be more brute forceable?