A data hiding method based on information sharing via PNG images for applications of color image authentication and metadata embedding

A new data hiding method via PNG images based on Shamir's (k, n)-threshold secret sharing scheme is proposed. The coefficients of the polynomial used by the Shamir's method are taken as carriers to carry given data. The data to be hidden then are transformed into partial shares and embedded into the alpha-channel plane of a cover PNG image. Undesired white noise created in the resulting stego-image is removed by skillfully mapping the computed share values into suitable ranges in the embedding process. An important application of the proposed method to color image authentication is also proposed, with detailed authentication algorithms for PNG images presented. Compared with existing methods, the proposed image authentication method possesses the merits of losslessness during image authentication, high sensitivity to image alterations, good tampering localization capability, and very low false acceptance and rejection ratios. Experimental results proving the effectiveness of the proposed methods are also included.

► The method uses secret sharing scheme cooperated with alpha channels to hide data.
► The color image authentication method has the characteristic of losslessness.
► The color image authentication method localizes tampered part at the pixel level.
► The color image authentication method surpasses existing methods in many aspects.