Expand description
Asymmetric Cryptography
Implements Ed25519 signatures (RFC 8032) and X25519 key exchange (RFC 7748).
§Implementation Details
Field arithmetic operates in GF(2^255-19) using a 5-limb representation with 51 bits per limb, giving us 255 bits total. This allows intermediate products to fit in u128 without overflow.
Ed25519 uses the twisted Edwards curve -x^2 + y^2 = 1 + dx^2y^2 where d = -121665/121666 mod p.
X25519 uses the Montgomery form of Curve25519 with the Montgomery ladder for constant-time scalar multiplication.
Modules§
- key_
exchange - X25519 key exchange