Cryptography and Network Security

Chapter 4

Data Encryption Standard

4.1 Simplified Data Encryption Standard

Simplified-data encryption standard (S-DES) was developed by Edward Schaefer as a teaching tool to understand data encryption standard (DES). S-DES is much similar to DES [1,2] in terms of ­operations performed and operators used in the encryption and decryption process. Moreover, S-DES uses simple operations and hence this algorithm is not used for real-time applications when compared to DES algorithm. In general, S-DES algorithm uses two basic operations for encryption as well as for decryption: substitution and permutation. In substitution technique, each element of the plaintext is substituted by another element. In permutation technique, the plaintext elements ...