Cipher key

Rather the network produces unique link-id's based on pseudonyms using pairing on block cipher key authentication [21].

The authors show that a single random byte fault at the input of the eighth round of the AES algorithm is sufficient to deduce the block cipher key. Simulations show that when two faulty ciphertexts pairs are generated, the key can be exactly deduced without any brute-force search.

In the Simeck family block cipher key schedule, Figure 2 shows the Simeck family block cipher key schedule as a block diagram.

KeyExpansion--round keys are derived from the cipher key using Rijndael's key schedule

The current cipher text is produced by current plain text, cipher key and former plain or cipher text.

The round key is derived from the cipher key using the key schedule algorithm.

The [f.sub.1] is the network authentication function, [f.sub.1] * is the re-synchronization message authentication function, it is used to provide data origin authentication for synchronization failure information sent by the USIM to the AuC, [f.sub.2] is the user authentication function, [f.sub.3] is the cipher key derivation function, [f.sub.4] is the integrity key derivation function, [f.sub.5] is the anonymity key derivation function for normal operation and [f.sub.5] * is the anonymity key derivation function for resynchronization, [f.sub.5]* is only used to provide user identity confidentiality during resynchronization.

At this time the cipher key space is the combination of different code elements in the benchmark sequence (assume that each code element length is m).

A cipher key is the method used to encode a plaintext and decode a ciphertext.

A key scheduling function is applied on every cipher key (KEY) update to generate the keys ([K.sub.j]) associated with each round.

Notice that, to use this method Playfair cipher key [SK], two random numbers seeds [R] and [K] are required for recovering the plaintext [P].