A self-synchronized chaotic image encryption scheme

•We introduce a fast chaotic self-synchronized image encryption scheme (1.5 improvement compared to the fastest existing one).•The scheme can be used in both synchronized and self-synchronized modes by choosing parameters.•The scheme passes well-known uniformity and randomness criteria.

In this paper, a word based chaotic image encryption scheme for gray images is proposed that can be used in both synchronous and self-synchronous modes. The encryption scheme operates in a finite field where we have also analyzed its performance according to numerical precision used in implementation. We show that the scheme not only passes a variety of security tests, but also it is verified that the proposed scheme operates faster than other existing schemes of the same type even when using lightweight short key sizes.