Constituent Structures Based Technique Of Natural Language Watermarking

There is an increasing need for software or in the worst case, hardware that allows for protection of ownership rights, and it is in this context where watermarking techniques come to our help. Perceptible marks of ownership or authenticity have been around for centuries in the form of stamps, seals, signatures or classical watermarks nevertheless, given current data manipulation technologies, imperceptible digital watermarks are mandatory in most applications. A digital watermark is a distinguishing piece of information that is adhered to the data that it is intended to protect, this meaning that it should be very difficult to extract or remove the watermark from the watermarked object. Since watermarking can be applied to various types of data, the imperceptibility constraint will take different forms, depending on the properties of the recipient (i.e., the human senses in most practical cases).This thesis aims to discuss natural language watermarking, which uses the structure of the sentence constituents in natural language text in order to insert a watermark. This approach is different from techniques, collectively referred to as"text watermarking,"which embed information by modifying the appearance of text elements, such as lines, words, or characters. The watermark is inserted in the text by using constituent structures from a parsed sentence. If the required watermark bit is not achieved, the sentence is modified by making synonym substitutions and synonym transformations such as passivization and clefting, which change the syntactic structure of a sentence with little effect on its meaning. The first step is to identify marker sentences whose successors are the sentences carrying the watermark. The system uses quadratic residues and well as pseudo random numbers...