Comment on “A novel chaos based optical image encryption using fractional Fourier transform and DNA sequence operation”

Abstract We numerically demonstrate that the optical image scheme using fractional Fourier transform and DNA sequence operation proposed recently by Farah et al. [Opt & Lasers Tech, 2020, 121: 105777] has the problem of using DNA xor operation and optical implementation. The original image cannot be decrypted completely accordingly to the inverse encryption process.