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

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.

Reversible Data Hiding in Encrypted Images With Distributed Source Encoding

“…To embed additional data into the image, the data-hider first decomposes the encrypted image E into four sub-images E (1) , E (2) , E (3) and E (4) , each sized…”

Recent Advances in Homomorphic Encryption: A Possible Future for Signal Processing in the Encrypted Domain

“…In parallel, other works developed some general tools for processing some particular operations on encrypted signals, which can be useful in many applications, e.g., Gram-Schmidt orthogonalization [13], discrete cosine transform computation [5], and discrete Fourier transform computation [6]. Finally, one can mention general discussions on the processing of encrypted signals [12] and attempts to find adequate representations for such processing, as in [7].…”

Analysis of a Buyer–Seller Watermarking Protocol for Trustworthy Purchasing of Digital Contents

“…the seller) who embeds his share of the watermark into the content has no idea what the final embedded watermark is. This technique is termed as watermarking in the encrypted domain [7]. As for who should generate the buyer watermark, there are two different techniques: -In the first technique introduced by Memon and Wong [18], a special trusted third party commonly known as the Watermark Certification Authority (W CA) was introduced to generate buyer watermarks, instead of letting the distributor to generate them; the WCA is fully trusted.…”