Résumé
The traffic of digital images has increased rapidly in the Internet. Security of image becomes important for many sectors mainly for medical applications. Nowadays, the transmission of medical images is a daily routine, especially over wireless (battlefields, traffic accidents, etc). Partial encryption is an approach to reduce the computational resources for huge volumes of multimedia data in low power network. This paper presents a method of partial or selective encryption for JPEG images. It is based on encryption of the quantified DCT coefficients . The purposed method results in a significant reduction in encryption and decryption processing time. It is fast and does not reduce the compression performance of the JPEG algorithm.