We propose a lightweight block cipher that supports 128-bit block size with 128-, 192- and 256-bit keys, to confirm with the Advanced Encryption Standard (AES) specification. All components of LCASE are chosen to be cellular automata-based so as to achieve higher parallelism and simplify the implementation. Apart from that, the other virtues of LCASE are its high speed and cheap cost along with being resistant against timing analysis attacks.