In this paper a novel fragile watermarking scheme is proposed to detect,
localize and recover malicious modifications in relational databases. In the
proposed scheme, all tuples in the database are first securely divided into
groups. Then watermarks are embedded and verified group-by-group independently.
By using the embedded watermark, we are able to detect and localize the
modification made to the database and even we recover the true data from the
database modified locations. Our experimental results show that this scheme is
so qualified; i.e. distortion detection and true data recovery both are
performed successfully.