code: public static Key generateKey(final Random random) {
          final byte[] signingKey = new byte[signingKeyBytes];
          random.nextBytes(signingKey);
          final byte[] encryptionKey = new byte[encryptionKeyBytes];
          random.nextBytes(encryptionKey);
          return new Key(signingKey, encryptionKey);
      }
docs: Generate a random key
  
  @param random
  source of entropy
  @return a new shared secret key