Academy of

Cryptography is a process of transforming original information into a format such that it is only read by the desired recipient. It is used to protect information from other people for security purpose. Visual cryptography is a method which is used to encrypt information in any format like text, image, led display such that decryption is done by human eye. It does not require any key for decryption. Visual cryptography is mainly of two types segment based visual cryptography, pixel based visual cryptography. Initially this method was developed only for monochrome images then it was upgraded to grey level and then coloured images. As it does not require any key to decrypt that is why this method is unbreakable. This method is useful in vast applications which handle high value assets. It can replace the second factor that is token or key in multifactor authentication system. It can be used in online shopping sites, online banking sites, government sites. This paper gives detailed survey of visual cryptography methods and their applications