利用数字指纹能够追踪非法使用多媒体内容用户。为此提出一种结合OFFO(正交向量构造最优聚焦指纹)指纹和BIBD(均衡不完全区组设计)编码的数字指纹方案。该方案以连续型OFFO指纹为基向量原型,并在保持不同指纹码间距离不变的情况下把连续型指纹量化为二值指纹,然后利用BIBD编码构造出新的多层编码指纹方案。理论分析和实验结果表明,与同类指纹方案相比,新的指纹方案在用户容量相同的情况下有更好的抗共谋攻击能力。

Digital fingerprinting is a technique for identifying users who use multimedia content for unintended purposes. This paper develops a new fingerprinting scheme based on OFFO (Optimal Focused Fingerprints from Orthogonality)and BIBD (Balanced Incomplete Block Design). This scheme considers OFFO as basic signal and transforms the continuous code into antipodal form of binary code, and uses balanced incomplete block designs to construct multilayer fingerprinting. Theoretical analysis and experimental results demonstrate that, compared with the similar fingerprinting scheme, the proposed scheme can more exactly identify at lest one of colluders with the same user number.