| In the era of knowledge economy,the rapid development of Internet has promoted the use and dissemination of digital resources,but the easy dissemination of digital products themselves,digital products can easily be compromised,causing losses to content providers.To solve this problem,digital fingerprinting technology was born.By secretly embedding a unique fingerprint into every digital copy distributed,content providers can track down pirates,protect the copyright of digital products and safeguard their legitimate interests.While some progress has been made in digital fingerprinting,there are still some pressing issues that need to be addressed,especially the anticollusion fingerprint construction and security flaws of symmetric fingerprinting schemes.Specifically,the current anti-complicity fingerprint has a low encoding efficiency.The symmetric fingerprinting scheme cannot determine whether the pirated digital copies originate from malicious distribution by illegal users or deliberate framing by content providers.To address the above two problems,this paper proposes a fingerprinting method based on identifiable parent property codes(IPP codes)and concatenated code,and designs an asymmetric digital fingerprinting scheme that can resist conspiracy attacks.The main work of this paper is as follows.On one hand,to address the difficulty in construction of anti-collusion fingerprints and difficulty in adjustment of code word length,this paper proposes a conspiracy-resistant fingerprint coding method based on IPP codes and concatenated code.This method uses the IPP code constructed based on the parsing matrix as the inner code and the outer code is IPP code with the Reed-Solomon code(RS code)as elements.A new anti-collusion fingerprint code is generated by these two codes using cascade coding.The cascaded code has good anti-collusion capability and is flexible in construction,so that the user can adjust the code length and code size as needed.On the other hand,to address the security shortcomings of the symmetric fingerprint scheme,an asymmetric fingerprint scheme based on homomorphic encryption is proposed in this paper.In the traditional symmetric fingerprinting scheme,the content provider has the fingerprints of all the purchasers,so when a pirated database is found,it is impossible to identify whether the pirated database is distributed illegally by the user or deliberately by the content provider to trap the user.In the asymmetric fingerprinting scheme proposed in this paper,the content provider no longer has the plaintext of the purchaser’s fingerprints,so it is impossible to frame the legitimate user.In the process of implementing the asymmetric fingerprinting scheme,fingerprint embedding and extraction are required,so this paper proposes an ESFCM(Equal Sized Fuzzy C-Means)based fingerprint embedding and extraction algorithm.Through ESFCM algorithm,the database is divided into several data clusters of close size,to better control the embedding position,embedding quantity and embedding strength of fingerprints and improve the robustness and security of digital fingerprint algorithm.The experimental results show that the anti-collusion fingerprint coding method proposed in this paper has good anti-collusion performance and the construction process is flexible.This coding method can meet the needs of users in terms of code word length and code word size.The asymmetric fingerprint method proposed in this paper can protect the interests of content providers and consumers and provide strong evidence to sanction dishonest users.Compared with similar algorithms,the ESFCM-based fingerprint embedding and extraction algorithm has better fingerprint robustness and the database after embedding fingerprints maintains better usability. |
