Input: a cover code, secret message , and random seed
Output: a marked code with the secret message and the length of the secret message
Step 1: determine the center of the mini program code and the length of each module
Step 2: establish a coordinate system and store module coordinates of encoding region in an array
Step 3: convert the secret message into a binary stream and compute its length :
Step 4: choose the embedded region based on the secret length , and determine the module to start modification according to the random number generated by random seed
Step 5: replace modules with from the start modification module continuously
Step 6: repeat Step 5 until all the bits are hidden in the cover code
