International Journal of Computer Theory and Engineering, Vol. 1, No.2, June 2009 1793-8201 - 188 - Abstract—In this paper, we proposed a reconfigurable secure image codec based on the Discrete Wavelet Transformation (DWT) and the Advanced Encryption Standard (AES) processor. Either, use of image coding with DWT or encryption using AES is well known. However, linking these two designs to achieve secure image coding is leading. The prominent feature of this method is a partial encryption of bass frequency (LL bands) by AES-128 (128-bit keys), or AES-192 or AES-256. Our approach provides considerable levels of security (key size, partial encryption, encryption mode), and has very limited adverse impact on the compression efficiency. The proposed codec can provide up to 9 cipher schemes within a reasonable software cost. Correlation, PSNR and compression rate results from these codec are analyzed Index Terms—AES, Band LL, DWT, Partial Encryption, Security Levels. I. INTRODUCTION In the digital world nowadays, the security of digital images/videos becomes more and more important since the communications of digital products over network occur more and more frequently. Since digital video transmission system usually includes a compression module that aims to reduce the transmitted bit rate, the cryptography techniques have to be carefully designed to avoid potential adverse impact on the compression efficiency, and on the functionalities that the compression format provides. The past decade, several efforts have developed image-video encryption schemes for secure information transfer. These techniques can be classified into three types according to the target data selected from compression stages. The first one is named “Spatial Domain” schemes, which apply encryption to the original information directly like [1]. The second scheme is named “Bitstream Domain”, which encrypts the code words of compressed Bitstream like [2]. To reduce the amount of processing overhead, the third schemes as know “Frequency Domain” has been proposed, which utilize the results of DCT or DWT transformation and quantization stages of compression process [3]. To deal with the amount of codec performance and intensive computation given by security mechanisms, this paper proposes a secure image codec configurable. We have proposed our codec by synthesis of the JPEG200 codec and the JPEG Codec. Manuscript received March 30, 2009. The authors are with the Electronics and Microelectronics Laboratory, Faculty of Sciences Monastir, 5000 Tunisia (corresponding author Medien. Zeghid: +216-73 501 785; fax: +216-73 501 785). Our codec present the bloc DWT of JPEG2000 and the bloc Huffman coding of JPEG. So, the sensibility of the Human Visual System (HVS) to DCT based image processing cause a lot error [4]. From this point of view the discrete wavelet transform (DWT) is a very attractive version of the frequency models for the HVS. The Huffman coding presents an advantage to be less complex and few calculations than EBCOT. The JPEG and JPEG2000 codec are presented and compared in [4]. Furthermore, we combine the compression and encryption into single process upon user need. We improved an approach called band LL encryption to reduce encryption and decryption time in image communication and processing. The encryption-decryption effects are achieved by the AES algorithm [5]. In our approach, AES is aim to encrypt group of LL bands. The prominent feature of this method is an encryption of LL bands by AES-128 (128-bit keys), or AES-192 (192-bit keys), or AES-256 (256-bit keys). Instead, we focus on a method that implements partial encryption of LL bands. Our codec can provide up to 9 cipher band LL encryption schemes. Using a security vector, the user can allot a precise security service of his application (security or no, encryption or decryption, key-length, full encryption or LLi band encryption, ECB or CBC mode). Our unified software design can run both our proposed image codec and the extended image codec as know secure image codec. The rest of this paper is organized as follows. Section 2 introduces our proposed image codec scheme and present results compression comparison of our codec with JPEG2000 and JPEG. In section 3, some blocs of our proposed secure images codec are presented. The first part of this section presents the AES algorithm and some necessary considerations concerning security levels of the cryptosystems. Another part presents the detailed description of the image encryption scheme. Also, the controller module is defined. The illustration of the performances and the efficiency of the proposed secure image codec through analysis security by statistical approach are described in section 4 and 5. Conclusions are drawn in section 6. II. PROPOSED IMAGE CODEC Our codec (figure 1) is hybrid, present the bloc DWT of JPEG2000 and the bloc Huffman coding of JPEG. This codec combines the advantages of these both norms. The wavelet transform has emerged as a cutting edge technology, within the field of image compression. Wavelet-based coding provides substantial improvements in picture quality at higher compression ratios [6]. Over the past few years, a DWT-AES Processor for a Reconfigurable Secure Image Coding D. Dia, M. Zeghid, M. Atri, B. Bouallegue, M. Machhout and R. Tourki