Abstract: Disclosed is a fragile watermarking scheme for detecting and localizing malicious alterations made to a database relation with categorical attributes without introducing distortions to cover data. A watermark for a tuple group may be inserted by selectively switching the position of tuples in tuple pairs using a tuple hash associated with each tuple in the tuple pair; and a corresponding bit in a watermark derived from the tuple group using a embedding key, a primary key and hash functions.

Abstract: A watermarking system embeds a watermark into data values that may be streamed. A data hash is calculated using data values and a hash key. The data values are grouped. The groups include a first group and a second group. A first group hash is calculated using data values in the first group and a first group hash key. A second group hash is calculated using data values in the second group and a second group hash key. A watermark is constructed based on the first group hash and the second group hash. The value of at least one of the data values in the first group is modified using the watermark.

Abstract: Data recovery methods for data recording applied to a storage medium. It is determined whether multimedia data is detected on the storage medium. If the multimedia data is detected, determining whether reconstruction of management information associated with the multimedia data is required for the storage medium according to the checking results. If the reconstruction of the management information is required, a recovery process is executed.

Abstract: A watermarking system embeds a watermark into data values that may be streamed. A data hash is calculated using data values and a hash key. The data values are grouped. The groups include a first group and a second group. A first group hash is calculated using data values in the first group and a first group hash key. A second group hash is calculated using data values in the second group and a second group hash key. A watermark is constructed based on the first group hash and the second group hash. The value of at least one of the data values in the first group is modified using the watermark.

Abstract: Disclosed is a fragile watermarking scheme for detecting and localizing malicious alterations made to a database relation with categorical attributes without introducing distortions to cover data. A watermark for a tuple group may be inserted by selectively switching the position of tuples in tuple pairs using a tuple hash associated with each tuple in the tuple pair; and a corresponding bit in a watermark derived from the tuple group using a embedding key, a primary key and hash functions.