Abstract
The paper presents an efficient image cryptosystem for dealing with low details gray scale images. The proposed image cryptosystem is based on using the RC6 encryption algorithm with various operation modes like ECB, CBC, OFB and CFB. The gray scale images is firstly divided into blocks of 128-bit. Then, the RC6 cipher algorithm is applied on 128-bit blocks in different modes of operation. The proposed strategy is inspected with different encryption key performance indicators like entropy, correlation coefficients, irregular deviation, histogram deviation, differential and noise immunity tests. Experimental tests ensure the superiority of the proposed encryption strategy for the encryption of small details images especially with OFB modes of operation. The achieved outcomes ensure the efficiency of the proposed encryption strategy in encrypting small details gray scale images.