An Efficient Adaptive Encryption Algorithm for Digital Images

Abstract

Abstract-This paper proposes an efficient method for encryption of digital images using an adaptive algorithm. According to the proposed algorithm the image used was segregated into significant and non significant blocks. For making the level of security different for different blocks, total and partial encryption has been utilized for the significant and non significant blocks respectively. Spatial as well as transform domain for the significant and non significant blocks respectively are used in this proposed method. The final encrypted image reflects the efficacy of the proposed algorithm. A comparative study between the conventional approaches of spatial and transform domain for the encryption of the image with the proposed encryption algorithm reveals the superior performance of the proposed algorithm. The experimental results suggest that the decrypted image is of excellent quality and signal to noise ratio is maintained well within the limit. The computational time utilized is very less as compared to the conventional approach, which suggests the enhanced overall performance and makes it suitable for high speed online applications.Index Terms-Arnold catmap, image encryption, logistic map, spatial and transform domain.