A Secure Asymmetric Optical Image Encryption Based on Phase Truncation and Singular Value Decomposition in Linear Canonical Transform Domain

Table 5

Quantitative comparison analysis.

Parameters	Ref [36]	Ref. [25]	Ref. [83]	Ref. [84]	Present scheme
Element in key space	9	6 (RPM + SPM)	6	6	DPM + RPM+6 (LCT order)
Entropy of the encrypted image	7.452	7.841	7.530	7.991	7.942
Execution time	3.80553 s	2.8371 s	—	—	1.515843 s