Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A watermark stored in a data file refers to a method for ensuring data integrity which combines aspects of data hashing and digital watermarking. Both are useful for tamper detection, though each has its own advantages and disadvantages.A typical data hash will process an input fil ...Full description
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A watermark stored in a data file refers to a method for ensuring data integrity which combines aspects of data hashing and digital watermarking. Both are useful for tamper detection, though each has its own advantages and disadvantages.A typical data hash will process an input file to produce an alphanumeric string unique to the data file. Should the file be modified, such as if one or more bit changes occur within this original file, the same hash process on the modified file will produce a different alphanumeric. Through this method, a trusted source can calculate the hash of an original data file and subscribers can verify the integrity of the data. The subscriber simply compares a hash of the received data file with the known hash from the trusted source. This can lead to two situations: the hash being the same or the hash being different.