High-efficiency optical image authentication scheme based on ghost imaging and block processing

Abstract

Ghost imaging (GI) is a hot technique in optical image encryption and authentication field due to its remarkable characteristics, such as strong ability against turbulence and high security. However, since the large number of private keys need to be stored and transmitted in the cryptosystems based on GI technique, the practical application of these cryptosystems is limited. To address this issue, we propose a high-efficiency optical image authentication scheme in which the private keys are a series of one-dimensional (1D) vectors used in block division. Each obtained reference intensity pattern behaves as a public key after being divided by two block-division vectors into blocks and further processed. Unlike the traditional GI based optical encryption and authentication schemes in which a series of two-dimensional (2D) phase-only masks (POMs) or reference intensity patterns are used as principal keys to be transmitted privately, the private keys in our proposed system to be transmitted are a series of 1D vectors. Consequently, the burden of the storage or transmission of private keys can be decreased considerably and high efficiency can be achieved. Since the numbers, sizes, repetition times and arrangement sequences of elements in the vectors could vary in a wide range, the vector selection possess high randomness, which guarantees the security of the proposed system. Using the private and the public keys, a correct reconstructed image and successful authentication result can be obtained by the authorized users. Numerical simulations are conducted to validate the feasibility, security and ability to resist noise and occlusion of the proposed scheme.