M' is the resultant encrypted message returned by second function [beta] after applying MLEA on message M using secret key K.
The MLEA consists of the following three different operations.
To illustrate the MLEA, we present a simple example.
Before data mapping, the carrier image is transposed, data is encrypted via MLEA, and then a 1-1 mapping between secret data bits and image pixels is maintained.
The extracted bits are decrypted by applying the reverse operations of MLEA and then converted into its original form.
The bits stream (E) is then decrypted using the reverse operations of MLEA and original secret message is achieved.