BLS12-381 for Ruby

gem 'bls12-381'

require 'bls'

# Generate private key.
private_key = SecureRandom.random_number(BLS::Curve::R - 1)

# Or you can use hex string.
private_key = '67d53f170b908cabb9eb326c3c337762d59289a8fec79f7bc9254b584b73265c'

# Generate public key from private key.
public_key = BLS.get_public_key(private_key)
# Public key is BLS::PointG1 object.
# If you want to use BLS::PointG2 public key, use BLS.get_public_key(p, key_type: :g2)

# sign and verify
message = '64726e3da8'

signature = BLS.sign(message, private_key)
# signature is BLS::PointG2 object. You can get signature with hex format using #to_hex method.
# If you want to use BLS::PointG1 signature, use BLS.sign(message, p, sig_type: :g1)
signature.to_signature

is_correct = BLS.verify(signature, message, public_key)
=> true

# Sign 1 msg with 3 keys
private_keys = [
  '18f020b98eb798752a50ed0563b079c125b0db5dd0b1060d1c1b47d4a193e1e4',
  'ed69a8c50cf8c9836be3b67c7eeff416612d45ba39a5c099d48fa668bf558c9c',
  '16ae669f3be7a2121e17d0c68c05a8f3d6bef21ec0f2315f1d7aec12484e4cf5'
]
public_keys = private_keys.map { |p| BLS.get_public_key(p) }
signatures2 = private_keys.map { |p| BLS.sign(message, p) }
agg_public_keys2 = BLS.aggregate_public_keys(public_keys)
agg_signatures2 = BLS.aggregate_signatures(signatures2)
is_correct2 = BLS.verify(agg_signatures2, message, agg_public_keys2)
=> true

# Sign 3 msgs with 3 keys
messages = %w[d2 0d98 05caf3]
signatures3 = private_keys.map.with_index { |p, i| BLS.sign(messages[i], p)}
agg_signatures3 = BLS.aggregate_signatures(signatures3)
is_correct3 = BLS.verify_batch(agg_signatures3, messages, public_keys)
=> true