Reversible image authentication using a central folding strategy with two images

In reversible image authentication (RIA) methods, it is common to use a reversible hiding method to embed the authentication code (AC) bits into each block of an original image to form a watermarking image. Since the reversible hiding methods have low embedding capacity, the authentication methods based on them have limited attack detection ability. In this paper, we use a dual-image reversible embedding method based on the central folding strategy with some slight improvements to construct an RIA method. Due to the large embedding capacity, low image distortion, no location map to be used, and AC bits generated by using hash function MD5 on block’s features, the proposed image authentication method can detect any type of attack with higher accuracy compared to existing methods. Its attack detection ability reaches \(100\%\) $100\%$ for block sizes of \(4\times 4\) $4\times 4$ , \(3\times 3\) $3\times 3$ , and \(99.91\%\) $99.91\%$ for a block size of \(2\times 2\) $2\times 2$ while maintaining high image quality.