An area-efficient high-speed AES S-box method
Rick F. Hobson, Scott Wakelin · 2005
The advanced encryption standard makes repeated use of a performance limiting randomization step, SubBytes, which invokes an S-box logic junction to scramble 8 data inputs. This paper introduces a new method for implementing S-box (and a variant, called T-box) logic functions. The method is as fast as previous methods, but uses only one quarter of the gates of other fast methods. In addition, the method can produce a differential output which helps to speed up downstream exclusive-or logic.