A method of providing anti-replay protection, authentication, and encryption with minimal data overhead is provided. A sender uses an arbitrary-length pseudorandom permutation to encrypt messages that include plaintext and successively increasing sequence numbers, to produce ciphertext messages. The sender transmits the ciphertext messages. A receiver receives the ciphertext messages and, for each received ciphertext message, performs the following operations. The receiver decrypts the given ciphertext message to recover plaintext and a candidate sequence number from the message. The receiver determines if the candidate sequence number is in any one of multiple non-contiguous acceptable sequence number windows having respective sequence number ranges that are based on at least one of a highest sequence number previously accepted and a last sequence number that was previously rejected, as established based on processing of previously received ciphertext messages.