An encryption apparatus and method that provide a mobile fast block cipher algorithm that supports low-power encryption. The encryption apparatus includes a user interface unit, a key scheduler unit, an initial conversion unit, a round function processing unit, and a final conversion unit. The user interface unit receives plain text to be encrypted and a master key. The key scheduler unit generates a round key from the master key. The initial conversion unit generates initial round function values from the plain text. The round function processing unit repeatedly processes a round function using the round key and the initial round function values. The final conversion unit generates ciphertext from the resulting values of the round function processed in a final round by the round function processing unit.