[Retracted] A Double-Layer Image Encryption Scheme Based on Chaotic Maps and DNA Strand Displacement

Table 4

Information entropy.

Information entropy	Proposed	Ref. [15]	Ref. [18]	Ref. [26]
Plain image	7.3740	—	—	—
Encrypted image	7.9971	7.9874	7.9971	7.9970