Efficient multiple secret visual cryptography via CA-rule 30

Visual Cryptography (VC) is a technique to hide visual information (images, printed text etc.) within images. This technique was introduced by Noar's in Eurocrypt-1994. It is a new type of secret sharing technique. This paper propose a visual cryptography scheme that encodes a set of T >= 2 secrets into two rectangular shares. The T secrets can be reconstructed one by one, by superimposing the second share and the circular shifted first shares with T different circular shift. It requires less storage space compared to different existing VC schemes because only one share store with first row of the secret image taken as password. At the time of decryption, this password will be expanded via cellular automata rule 30 up to stored share size. As result shows recovered secret image may get distorted but still it is efficient and more secure as compare to the existing multiple secret VC scheme, due to the less storage requirement and random pattern generation through cellular automata.