Partial encryption on SPIHT compressed images

Abstract

Recently, Multimedia security paradigm has shifted towards encryption techniques combined with compression systems to meet the constraints of wireless networks. Several techniques of encryption with compression have been proposed to reduce processing time, but either they are insecure or computationally intensive. An efficient partial encryption technique based on SPIHT compressed bitstream is thus proposed to provide an efficient encryption for digital images. A satisfactory level of security is achieved with encryption of less than 0.5% of data for image encoded at 0.8 bpp by encrypting the bits as well as their locations. The proposed technique has large key space and can withstand approximation and brute force attacks. © 2009 Springer-Verlag Berlin Heidelberg.