* each key and return the three results in a sequential [].
*/
private byte[] calcResponse(byte[] key, byte[] text)
throws GeneralSecurityException {
assert key.length == 21;
DESKeySpec dks1 = new DESKeySpec(makeDesKey(key, 0));
DESKeySpec dks2 = new DESKeySpec(makeDesKey(key, 7));
DESKeySpec dks3 = new DESKeySpec(makeDesKey(key, 14));
SecretKey key1 = fac.generateSecret(dks1);
SecretKey key2 = fac.generateSecret(dks2);
SecretKey key3 = fac.generateSecret(dks3);
cipher.init(Cipher.ENCRYPT_MODE, key1);
byte[] out1 = cipher.doFinal(text, 0, 8);