Optical encryption of digital data

Smart-pixel architectures, which use the cells of field-programmable gate a rrays to provide electronic functionality and intraplane communication, off er a general-purpose approach to exploiting new application areas that woul d benefit from this kind of structure. One such area, that of the encryptio n of digital data, is discussed here. Some of the characteristics exhibited by encryption algorithms and ways in which these are applicable to smart-p ixel technology are described. The implementation of an algorithm in curren t use, the SAFER K-64, and its interfacing to an electronic host are then c onsidered in detail. It is shown that this encryption algorithm maps well o nto smart-pixel technology because it involves only parallel data transfers , simple regular operations, and interconnections plus a relatively low rat e of transfer to the host. (C) 2000 Optical Society of America. OCIS codes: 200.0200, 200.3760.