Research On Digital Signature Algorithm Based On Text Semantic Watermarking

The rapid development and wide application of computer technology, communications technology and network technology (especially the Internet) have had a tremendous impact on the traditional working methods and business models, but also contributed to e-business manner, mode, and the system came into being. Compared with the traditional business model, e-commerce has the advantages of being convenient, low cost, and more efficient, which makes it play an increasingly important role in today's economy and trade.However, as e-commerce systems is highly dependent on computer network technology, while the Internet has the features of free and open, which make the e-commerce systems facing with a wide range of security risks and threats inevitably. In order to protect the legitimate rights and interests of trading parties effectively, it is a matter of course to urgently demand that e-commerce system must have high reliability, strong security to ensure that the integrity, security, timeliness, privacy, and non-negative of the data transmission business.Digital signature technology, as the core technology of verifying the identity of e-commerce transactions and can not denying the authenticity the transaction, is an important component of protecting the e-commerce's security.For the shortcoming of signature information being easily removed from digital signature, the paper proposes a semantic watermarking-based algorithm which is based on natural language processing technology. The basic idea of the algorithm is that on the premise of not making any changes to the semantics of the text, digital signature information is embedded with the synonymy substitution algorithm. In addition, in the stage of data encryption, the comprehensive use of DES algorithm and RSA algorithm make the cracking and tampering of signature information more difficult. Experiments testify that the algorithm has the advantages of being easy to realize, good robustness and strong anti-testing.The main research work includes the following:First of all, traditional cryptography algorithm is researched and compared. Then, according to the features and the actual needs of symmetric key algorithms and asymmetric key encryption algorithm, the digital signature protocol is proposed based on the combination of DES algorithm and RSA algorithm, which can solve single encryption algorithm's problems in processing efficiency, password management, etc. Secondly, for the shortcoming of weak anti-aggressive, poor robustness and hidden, a text semantic-based digital watermarking algorithm is proposed based on synonymy substitution. The basic principle of the algorithm is that on the premise of not making any changes to the semantics of the text, digital signature information is embedded with the synonymy substitution algorithm. Experiments show that when comparing with traditional algorithm, the algorithm has better robustness and is more anti-testing.Third, the protocols and algorithms proposed in this paper are realized on a digital signature system. Experiments show that this method is feasible and effective.