The Optical Encryption of Digital Data

Linda E. M. Brackenbury and Kenneth M. Bell

Abstract

Smart pixel architectures, using the cells of Field Programmable Gate Arrays to provide the electronic functionality and intra-plane communication, offer a general purpose approach to exploiting new application areas that would benefit from this structure. One such area, that of the encryption of digital data, is discussed in this paper. Some of the characteristics exhibited by encryption algorithms and how these are applicable to smart pixel technology are described. The implementation of an algorithm in current use, the SAFER K-64, and its interfacing to an electronic host are then considered in detail. It is shown that this encryption algorithm maps well onto smart pixel technology since it involves only parallel data transfers, simple regular operations and interconnections plus a relatively low transfer rate to the host.