A scheme of betrayal checking and traitor tracing for confidential image in Internet

It is an important aspect of information security for institutions to keep secret for confidential documents in Internet environment. In this paper, we put forward a scheme of betrayal checking and traitor tracing for confidential image in Internet. In the scheme, we divide users into user groups, generate a type of anti-collusion attack fingerprint code based on BIBD code, and assemble branches of institution into a serial of sub-organization and distribute corresponding organization´s watermarking. Next, we embed the fingerprint and watermarking into the confidential images. Then, we collect image in Internet regularly, check suspected image by organization´s watermarking and locate the source confidential image by image feature. Finally, we trace the traitor by encode the fingerprint codeword. Experiment verifies the validity of this scheme.