A Novel Technique for a Power of Two Based S-Box Implementation

The S-Box is one of the major steps of the Advances Encryption Standard. Its entries are pre-computed and stored on read-only-memory lookup tables to avoid tedious real time computations using Galois Field. However, such setup is not a use-anytime any environment standard. On the one hand,storing entries of the S-Box may not be desirable for some environments. On the other hand, real time computing of the same may not be desirable either. This paper suggests a distributed environment that is reasonable for on the fly computing of the byte substitution data. The environment deploys a linear relationship between the substituting and substituted bytes. Nevertheless, added security measures and ease of implementation trades off the security imbalance.