Abstract: Cryptography, in general, is a process of transforming original information into a format such that it is only read by the desired recipient .Visual cryptography(VC) scheme is a cryptographic technique which allows visual information to be encrypted in such a way that the decryption can be performed by the human visual system, without the aid of computers. 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 techniques and their applications.
Keywords: Visual cryptography, secret sharing, image encryption, VC applications.