Software Data Encryption Standard
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
A method is described for implementing the Data Encryption Standard (DES) on the Intel 8088, 8086 or 80286 microprocessors. The same technique could be used on any processor. Data encryption techniques must be implemented to run efficiently and compile to small programs requiring minimum amounts of storage to avoid impacting a functioning system. Many software implementations exist for the DES; however, the method described performs faster and requires less storage. The DES is defined in Federal Information Processing Standard (FIPS) Publication 46 and requires the permutation of 32 bits sixteen times per eight-byte block encrypted. This disclosure does away with the actual work of permutation during encryption by using pre-computed tables.