Robust Image Content Authentication Using Perceptual Hashing and Watermarking

Abstract

Perceptual hashing is a promising tool for multimedia content authentication. Digital watermarking is a convenient way of data hiding. By combining the two, we get a more efficient and versatile solution. In a typical scenario, multimedia data is sent from a server to a client. The corresponding hash value is embedded in the data. The data might undergo incidental distortion and malicious modification. In order to verify the authenticity of the received content, the client can compute a hash value from the received data, and compare it with the hash value extracted from the data. The advantage is that no extra communication is required – the original hash value is always available and synchronized. However, on the other hand, image quality can be degraded due to watermark embedding. There is interesting interaction between hashing and watermarking. We investigate this issue by proposing a content authentication system. The hash algorithm and the watermarking algorithm are designed to have minimal interference. This is achieved by doing hashing and watermarking in different wavelet subbands. Through extensive experiments we show that the parameters of the watermarking algorithm have significant influence to the authentication performance. This work gives useful insights into the research and practice in this field.