Reversible Fragile Watermarking for Fine-Grained Tamper Localization in Spatial Data

Spatial data has been widely used in many areas. Meanwhile, the increasingly simplified data access and manipulation methods in spatial data related applications make it important to verify data truthfulness. In this paper, we propose a reversible fragile watermarking scheme for the content authentication of spatial data. The proposed scheme embeds (detects) four kinds of watermarks, i.e., group, object, vertex-local and vertex-global watermarks, into (from) each object (vertex) by altering the digits of the coordinates after the LSD (Least Significant Digit). According to the detection results of those four kinds of watermarks, the scheme can not only locate tampers, but also recognize modification types on both object and vertex levels. In addition, the proposed scheme is reversible, that is the original data can be restored from the watermarked data. The feature of reversibility makes the scheme suitable for applications which require high-precision data.