Recovery from decryption errors in a sequence of communication packets

Apparatus for decrypting encrypted data, comprising:

• a receiver front end, which is configured to receive from a transmitter a sequence of communication packets, which carry data encrypted with an encryption scheme that depends on a counter value that is incremented by the transmitter;
• and
• a decryption unit, which is configured to attempt to decrypt the data of a received packet multiple times using different, respective counter values so as to produce multiple respective decrypted outputs, to identify among the multiple decrypted outputs, after the multiple decrypted outputs have been produced, a decrypted output in which the data has been decrypted correctly, and to recover the data of the received packet from the identified decrypted output.