EURASIP Journal on Information Security 
Volume 2007 (2007), Article ID 78943, 20 pages
doi:10.1155/2007/78943
Review Article

Protection and Retrieval of Encrypted Multimedia Content: When Cryptography Meets Signal Processing

Zekeriya Erkin,1 Alessandro Piva,2 Stefan Katzenbeisser,3 R. L. Lagendijk,1 Jamshid Shokrollahi,4 Gregory Neven,5 and Mauro Barni6

 1Electrical Engineering, Mathematics, and Computer Science Faculty, Delft University of Technology, 2628 CD, Delft, The Netherlands
2Department of Electronics and Telecommunication, University of Florence, 50139 Florence, Italy
3Information and System Security Group, Philips Research Europe, 5656 AE, Eindhoven, The Netherlands
4Department of Electrical Engineering and Information Sciences, Ruhr-University Bochum, 44780 Bochum, Germany
5Department of Electrical Engineering, Katholieke Universiteit Leuven, 3001 Leuven, Belgium
6Department of Information Engineering, University of Siena, 53100 Siena, Italy
Received 3 October 2007; Revised 19 December 2007; Accepted 30 December 2007

Recommended by Fernando Pérez-González

Abstract

The processing and encryption of multimedia content are generally considered sequential and independent operations. In certain multimedia content processing scenarios, it is, however, desirable to carry out processing directly on encrypted signals. The field of secure signal processing poses significant challenges for both signal processing and cryptography research; only few ready-to-go fully integrated solutions are available. This study first concisely summarizes cryptographic primitives used in existing solutions to processing of encrypted signals, and discusses implications of the security requirements on these solutions. The study then continues to describe two domains in which secure signal processing has been taken up as a challenge, namely, analysis and retrieval of multimedia content, as well as multimedia content protection. In each domain, state-of-the-art algorithms are described. Finally, the study discusses the challenges and open issues in the field of secure signal processing.