cardRr = bytes_to_num(&receivedCmd[4], 4) ^ crypto1_word(pcs, 0, 0);
// test if auth OK
if (cardRr != prng_successor(nonce, 64)){
cardRr = bytes_to_num(&receivedCmd[4], 4) ^ crypto1_word(pcs, 0, 0);
// test if auth OK
if (cardRr != prng_successor(nonce, 64)){