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A novel evaluation method for perceptual hash algorithm in authentication mode

Perceptual hash is an important research branch of multimedia security, while the evaluation of performance of a perceptual hash algorithm is not well studied so far. The traditional performance of a perceptual hash algorithm is robustness and discriminability. Such evaluation criterion is not good enough to judge an algorithm, especially for a perceptual hash algorithm working in authentication mode. In this paper, anew evaluation method is proposed to evaluate an authentication oriented perceptual hash algorithm by the capability of distinguish the malicious tamper from content preserving operations. A new performance, Identical Perceptual Distance, is also defined to quantize the ability. The thorough test on several representative published perceptual hash algorithms shows the feasibility of the proposed evaluation method.