Cryptography General Question:

The Software-optimized Encryption Algorithm (SEAL) was designed by Rogaway and Coppersmith in 1993 as a fast stream cipher for 32-bit machines. SEAL has a rather involved initialization phase during which a large set of tables is initialized using the Secure Hash Algorithm. However, the use of look-up tables during keystream generation helps to achieve a very fast performance with just five instructions required per byte of output generated.