Example twisted Edwards curves digital signatures with JWTs.

ed25519.rb

# gem install jwt rbnacl

require 'jwt'
require 'securerandom'

payload = {
  'signed' => 'Cicadoidea'
}

##
# Sign your payload.
signing_key = RbNaCl::Signatures::Ed25519::SigningKey.new SecureRandom.bytes 32
signature = signing_key.to_bytes # Save your signature to sign other things.
password = signing_key.verify_key.to_bytes # Use your password to authenticate.
signed_payload = JWT.encode payload, signing_key, 'ED25519' # Share the signed payload.

##
# Authenticate your signed payload.
verify_key = RbNaCl::Signatures::Ed25519::VerifyKey.new password
authenticated_payload, _ = JWT.decode signed_payload, verify_key, true, {algorithm: 'ED25519'}