Speckle Coding for Optical and Digital Data Security Applications
Arvind Kumar, Madan Singh, Kehar Singh · 2011
This chapter describes certain speckle coding techniques for optical and digital data security applications. It reviews various optical encryption and decryption methods. To make the optical data more secure, double random patterns may be used. In the double random phase encoding (DRPE) method, two statistically independent random phase masks are used for encryption, one in the input plane and another in the Fourier plane of a 4-f imaging setup. These have been used as a coding tool for storing data. The chapter provides the results of investigation of an encryption technique using phase image for encryption and a sandwich phase mask made by using elongated speckle patterns as the key. It also provides the results of multiplexing in optical encryption of two dimensional (2D) images using an aperture system in the Fourier plane of a DRPE system. Controlled Vocabulary Terms encoding; security of data; speckle