alt Hacker Newsthere must be tons of functions that are easy to process one way but almost impossible the other.
i get the feeling there is more to it than finding such a function, but the article doesnt get into that
there must be tons of functions that are easy to process one way but almost impossible the other.
i get the feeling there is more to it than finding such a function, but the article doesnt get into that
You also need the group structure, ie. a(bG) = b(aG) = (ab)G.
But AFAICT, elliptic curve groups really are the best known groups where DH is hard. The "Why curves win" section talks about it terms of key size, but the reason other groups require larger keys is they have some kind of structure which can be exploited to attack the "hard" direction (eg. in a finite field, the ability to factor over primes can be used to solve discrete logs), so the group size has to go up to compensate.