ed25519-donna is an implementation of the Ed25519 public-key signature algorithm by Dan J Bernstein.
Ed25519 is a 256-bit strength elliptical curve with 32-byte secret/public keys and 64-byte signatures.
It is very fast, easy to implement securely in software, and fully public-domain.
Downloaded 12/12/2013 from https://github.com/floodyberry/ed25519-donna
Filenames containing VALVE are *not* entirely public domain - see individual files for details.