Multimedia Security 2

4Image Crypto-Compression

Vincent ITIER¹, Pauline PUTEAUX² and William PUECH²

¹CRIStAL, University of Lille, CNRS, IMT Lille Douai, France

²LIRMM, Université de Montpellier, CNRS, France

The growing popularity of social networks and cloud computing has greatly increased the number of Joint Photographic Experts Group (JPEG)-compressed image exchanges. In this context, the security of the transmission channel and/or online storage can be sensitive to privacy leaks. Selective encryption is an effective tool for masking image content and protecting privacy while remaining consistent with the image encoding format. JPEG image encryption, also known as JPEG image crypto-compression, defines methods for encrypting a portion of the image content while still respecting the JPEG format. These methods provide a level of visual privacy while attempting to limit the file size expansion compared to classic JPEG compression. This type of method, which appeared in the early 2000s, relies on different approaches to implement the basic principles of cryptography. More recently, the question of security against decryption attacks has been the subject of increasing attention. Image processing in the crypto-compressed domain, that is, without decryption, is another new area of work.

4.1. Introduction

Over the past decade, increasing use of online storage (the cloud) and the sharing of data over networks has led to a growing demand for security and privacy with respect to personal data; the EU’s ...