A High-Speed Software DES Implementation

This paper describes a high-speed software implementation of the Data Encryption Standard (DES) cipher algorithm and the design tradeoffs necessary for high-speed operation. Many of the techniques presented in this paper may be applicable to other product ciphers. 1 Introduction Data security is becoming more important as more information is sent across networks. Once information is injected into the network, it may be intercepted in any number of locations. One way to protect information, whether it is transmitted or remains on a host computer, is to encrypt it. A popular form of encryption is the Data Encryption Standard or DES. This paper describes a high-speed software implementation of the DES encryption algorithm. The encryption rate on a DEC 3100 or a Sun 4 is about 1.1 megabits per second. The implementation and the design tradeoffs necessary for high-speed encryption are described. Many of the techniques used in this paper may be applicable to other product ciphers. The first..