ed25519.rb is a Ruby binding to the Ed25519 elliptic curve public-key signature
system described in RFC 8032.

Two implementations are provided: a MRI C extension which uses the "ref10"
implementation from the SUPERCOP benchmark suite, and a pure Java version based
on str4d/ed25519-java.

Ed25519 is one of two notable algorithms implemented atop the Curve25519
elliptic curve. The x25519 gem is a related project of this one, and implements
the X25519 Diffie-Hellman key exchange algorithm on the Montgomery form of
Curve25519.