Curve25519 is a state-of-the-art Diffie-Hellman function suitable for a wide
variety of applications.

Given a user's 32-byte secret key, Curve25519 computes the user's 32-byte public
key. Given the user's 32-byte secret key and another user's 32-byte public key,
Curve25519 computes a 32-byte secret shared by the two users. This secret can
then be used to authenticate and encrypt messages between the two users.

WWW: https://metacpan.org/release/Crypt-Curve25519