Non-expanded visual cryptography scheme with authentication

In recent years, a crucial issue is the manner in which to safely transmit the secret information and prevent the detection of information. An extended visual cryptography with authentication technology for the original image was proposed in previous studies. Fang and Lin´s scheme [3] combine the principle of traditional visual cryptography with authentication characteristic, when we fix the first share image and shift the other share image for certain unit, we can obtain the extra confidential data. But in traditional visual cryptography, secret pixels are expanded to cause the size of the recovered image is larger than the original one. So this study combined the non-expanded scheme with the extra ability of hiding confidential data to prevent the detection of information.