In the proposed AEAD scheme, the secret key is used to generate s-boxes and round keys and also to initialize the mask register. The remaining operations consist of Bitwise operations that have constant execution time.
16 eight-bit mask registers are first initialized based on the secret key and nonce and then modified by a chaotic function.
The aead_encrypt algorithm is shown in Figure 4, where a is the number of A blocks, m is the number of M blocks, a represents intermediate tags, [[summation].sub.M] is the checksum, and [lambda][i] is the set of mask registers for block-i of data.
(1) Input: 8-bit mask registers [[lambda].sub.j] for 0 [less than or equal to] j < 16, 32-bit initial values x and y, 32-bit perturbation values p and q, round/block number i.