Recent development in the digital system shows that data security is most important and that optical encryption can be used not only to keep signals confidential but also to authenticate information. By integrating sparsity constraint with optical encryption, the reconstructed decoder image is not always visually recognizable, but can be authenticated using optical correlation means methods. Traditional optical encryption methods can add an extra layer of security to this design as it authenticates without leaking primary signal information. This paper discusses advances in optical authentication and includes theoretical principles and implementation examples to demonstrate the workings of typical authentication systems. Benchmarking and upcoming possibilities are discussed and it is hoped that this review work useful in advancing the field of optical safety.