Journal of Multimedia Processing and Technologies Rabab Beniani, Kamel Mohamed FARAOUN 9 3 2018 https://doi.org/10.6025/jmpt/2018/9/3/88-101 http://www.dline.info/jmpt/fulltext/v9n3/jmptv9n3_2.pdf In this paper, we propose a new scheme for joint compression and encryption of digital images, based on cellular automata and selective encryption of quantized DCT coefficient. Using a key stream by a cellular automata mechanism, a subset of quantized coefficients is selected and then ciphered with the produced pseudorandom key-stream. Thus, we achieve a sufficiently robust security level, mostly against known plaintext attacks while preserving a high compression ratio. Several performance analysis including security analysis, speed performances and compression ratio are performed, and demonstrate the efficacy of the proposed approach with respect to existing ones.