An advanced encryption system (AES) architecture includes a maximum parallel encryption module which implements one round of the AES algorithm in one clock cycle, and a maximum parallel key scheduling module which generates sub-keys in one clock cycle in parallel with the encryption module, thereby permitting feedback modes of operation to be used without adversely affecting AES throughput. A controller controls the operation of the encryption and key scheduling modules such that one round is completed per clock cycle. The controller is preferably part of a hierarchical distributed control scheme comprising communicating finite state machines (FSMs). The architecture also preferably includes asynchronous input and output buffers.