NAME Crypt::Ed25519 - bare-bones Ed25519 public key signing/verification system SYNOPSIS use Crypt::Ed25519; # no symbols exported # generate a public/private key pair once ($pubkey, $privkey) = Crypt::Ed25519::generate_keypair; # sign messages $signature = Crypt::Ed25519::sign $message, $pubkey, $privkey; # verify message $valid = Crypt::Ed25519::verify $message, $pubkey, $signature; # verify, but croak on failure Crypt::Ed25519::verify_croak $message, $pubkey, $signature; DESCRIPTION This module implements Ed25519 public key generation, message signing and verification. It is a pretty bare-bones implementation that implements the standard Ed25519 variant with SHA512 hash, as well as a slower API compatible with the upcoming EdDSA RFC. The security target for Ed25519 is to be equivalent to 3000 bit RSA or AES-128. The advantages of Ed25519 over most other signing algorithms are: small public/private key and signature sizes (<= 64 octets), good key generation, signing and verification performance, no reliance on random number generators for signing and by-design immunity against branch or memory access pattern side-channel attacks. More detailed praise and other info can be found at . Ed25519 API ($public_key, $private_key) = Crypt::Ed25519::generate_keypair Creates and returns a new random public and private key pair. The public key is always 32 octets, the private key is always 64 octets long. $signature = Crypt::Ed25519::sign $message, $public_key, $private_key Generates a signature for the given message using the public and private keys. $valid = Crypt::Ed25519::verify $message, $public_key, $signature Checks whether the $signature is valid for the $message and $public_ke. Crypt::Ed25519::verify_croak $message, $public_key, $signature Same as "Crypt::Ed25519::verify", but instead of returning a boolean, simply croaks with an error message when the signature isn't valid, so you don't have to think about what the return value really means. EdDSA compatible API The upcoming EdDSA draft RFC uses a slightly different (and slower) API for Ed25519. This API is provided by the following functions: $secret_key = Crypt::Ed25519::eddsa_secret_key Creates and returns a new secret key, which is always 32 octets long. The secret key can be used to generate the public key via "Crypt::Ed25519::eddsa_public_key" and is not the same as the private key used in the Ed25519 API. $public_key = Crypt::Ed25519::eddsa_public_key $secret_key Takes a secret key generated by "Crypt::Ed25519::eddsa_secret_key" and returns the corresponding $public_key. This public key corresponds to the public key in the Ed25519 API above. $signature = Crypt::Ed25519::eddsa_sign $message, $public_key, $secret_key Generates a signature for the given message using the public and secret keys. $valid = Crypt::Ed25519::eddsa_verify $message, $public_key, $signature Crypt::Ed25519::eddsa_verify_croak $message, $public_key, $signature Really the same as "Crypt::Ed25519::verify" and "Crypt::Ed25519::verify_croak", i.e. the functions without the "eddsa_" prefix. These aliases are provided so it's clear that you are using EdDSA and not Ed25519 API. CONVERTING BETWEEN Ed25519 and EdDSA The Ed25519 and EdDSA compatible APIs handle keys slightly differently: The Ed25519 API gives you a public/private key pair, while EdDSA takes a secret and generates a public key from it. You can convert an EdDSA secret to an Ed25519 private/public key pair using "Crypt::Ed25519::generate_keypair": ($public_key, $private_key) = Crypt::Ed25519::generate_keypair $secret IMPLEMENTATIOIN This module currently uses "Nightcracker's Ed25519" implementation, but the interface is kept implementation-agnostic to allow usage of other implementations in the future. AUTHOR Marc Lehmann http://sfotware.schmorp.de/pkg/Crypt-Ed25519.html