Shenchuan Liu

A leakage suppressed two-level security visual secret sharing scheme

This paper proposes a new scheme of visual secret sharing which serves two-level security for color images. The proposed scheme splits a secret color image into four pieces referred to as shares; a black-and-white mask share and three color component shares, namely, red, green, and blue. All shares in this scheme are random binary images and each share is delivered to a different user to keep the image secret. In the scheme, the secrecy of the image can remain intact even three color component shares are gathered, that is, two-level security is served. The conventional scheme having the above mentioned features has the risk of information leakage even without the mask share. In contrast, the proposed scheme suppresses the possibility of information leakage in exchange for introducing low contrast recovered images.

A Cheat-Prevention Visual Secret Sharing Scheme with Efficient Pixel Expansion

A visual secret sharing (VSS) scheme with minimum pixel expansion is proposed to prevent malicious participants from deceiving an honest participant. A VSS scheme encrypts a secret image into pieces referred to as shares where each participant keeps a share so that stacking sufficient number of shares recovers the secret image. A cheat prevention VSS scheme provides another piece for each participant for verifying whether the shares presented by other participants are genuine. The proposed scheme improves the contrast of the recovered image and cheat-prevention functionality by introducing randomness in producing pieces for verification. Experimental results show the effectiveness of the proposed scheme.

A cheat preventing method with efficient pixel expansion for Naor-Shamir's visual cryptography

This paper proposes a cheat-prevention method of visual cryptography (VC) for binary images. A VC technique encrypts a secret image into images referred to as shares so that stacking sufficient shares recovers the secret image, where shares are kept by different parties. The proposed method prevents malicious parties from deceiving an honest party, i.e., from cheating the honest party. To fight cheating, no further pixel expansion is introduced to the proposed method, so this method improves the contrast of recovered secret image and cheat-prevention functionality.