Method for embedding secret message into PNG image

A method for embedding a secret message into a portable network graphics image in a computer readable medium comprising steps of:

• executing a processor to separate the portable network graphics image into a red channel, a green channel, a blue channel, and an alpha channel, the alpha channel defining a transparency channel;
• wherein values of said alpha channel range from 0 to 255 of a decimal system, and wherein said “0” denotes “opaque” and said “255” denotes “full transparency”;
• converting a secret message into a plurality of secret codes;
• converting said secret codes into a plurality of secret shares;
• wherein said secret shares are expressed by simultaneous equations containing said secret codes;
• sequentially embedding said secret shares representing the encoded secret message into the alpha channel of the portable network graphics image to define a modified alpha channel;
• modifying values of said secret shares as a function of a user predetermined value, said predetermined value selectively chosen to make transform each of the values of said secret shares from a first transparency value to a second transparency value to approach a full-transparent value of said alpha channel;
• and
• recomposing the red channel, the green channel, the blue channel and the modified alpha channel to define a secret embedded portable network graphics image;
• wherein the portable network graphics image and the secret embedded portable network graphics image are visually substantially similar.