SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
random.setSeed(encryptKey.getBytes());
kgen.init(128, random);

    def sha1_prng(key)
      key = OpenSSL::Digest.digest("SHA1", key)
      key_bytes = OpenSSL::Digest.digest("SHA1", key).bytes[0..15]
      for i in 0...key_bytes.size
        if key_bytes[i] > 128
          key_bytes[i] = key_bytes[i] - 256
        end
      end
      key_bytes.pack('c*').force_encoding("UTF-8")
    end