4 ms·
Note that I'm using the Elliptic Curve Diffie-Hellman (ECDH) exchaneg, which is an additive group. That's how I can get the shared keys down to a small size.
by boris1 5y ago
Note that I'm using the Elliptic Curve Diffie-Hellman (ECDH) exchaneg, which is an additive group. That's how I can get the shared keys down to a small size.
- anon_tor_12345 5y agoA group is a group. Doesn't matter whether you call it additive or multiplicative. So DH doesn't change since either way g^a and a*g are both defined as repeated action of g on g via the group operation. ECDH has smaller keys because the attacks are (until now) weaker and not because you're using an additive cyclic group.
- boris1 5y agoYes, just do not write (mod p), as it can be misleading to the reader. A mathematician doesn't care, but in RFCs they call the (mod p) groups a "prime group" to differentiate it from the Elliptic Curve group. (In fact, I think they call them "prime fields", not merely groups). I think the keys can be smaller because every random coordinate is a valid value (valid key), but in the case of RSA, valid values are more sparse.