Information Sciences and Computer Engineering, Vol. 2, No. 2, (2011) 19–23 International Journal of Information Sciences and Computer Engineering journal homepage: http://www.ijisce.org Data security in medical information system Mustapha Machkour a,b* , Youness Idrissi Khamlichi b,c , Karim Afdel a,b a Department of Mathematics and Computer Sciences, Faculty of Sciences, Agadir, Morocco b Laboratory of the Computing Systems and Vision, Faculty of Sciences, Agadir, Morocco c Department of Computer Sciences, National School of Applied Sciences, Khouribga, Hassan 1 University, Morocco Abstract– The database systems use the mechanisms of granting and revok- ing privileges and of authorization control to ensure the security of data. However, some users such as administrators or persons in charge of secu- rity have access to comprehensive content of database including patient‘s information that are of intimate nature and must be discreet. To enhance the security and avoid illegal access of such users, we propose in this arti- cle a mechanism using the content-based watermarking technique. Patient’s information are encrypted and inserted in an image associated to it. This image, with faculties of object-relational and object-oriented databases, is directly integrated into the database. To check the integrity of the image we use the edge map and invariant moments. Keyword: Confidentiality; Integrity; Watermarking; Edge; cryptography; BLOB 1 Object; mammography images. 1. Introduction Data security in medical information system has become a pri- ority for citizens and for government [1]. The need to accumu- late, share and analyze personal data is multiple: to improve the quality of care through electronic medical record. Throughout the world, governments adopt specific laws to protect the per- sonal data [2, 3, 4, 5]. However, it is hard to translate these laws into persuasive technology to ensure their implementation. Data security has three main properties: confidentiality, in- tegrity and availability. Overall, the property of confidentiality prevents illegal access. The property of integrity guarantees de- tection of any modification of data, whether accidental or ma- licious. Finally, the property of availability protects the system against the attacks of denial of service. Many articles treat and show the importance of security of medical data but don’t propose means or techniques for imple- menting this security [1]. In this paper, to implement our se- cure system, we used the invariant moments, the separation of bit planes of the image and the Blob object. * Corresponding author: Email: machkour@hotmail.com, Ph: 00212 668805720 1 Binary Large OBject :Data Type on binary format for unstructured Data :Im- age, Video. . . In this article we present a secured system for medical database. The security mentioned in this paper is primarily con- cerned with the integrity and confidentiality of data. In the first paragraph, we describe the functionalities of this system in par- ticular the one of watermarking used like an additional mean to enhance the integrity and confidentiality in database system. In the second part, we present the schema of the database. The third paragraph includes a description of the implementation of this system. 2. Functionalities of the system Our system includes the basic functionalities of any informa- tion management system to insert, view and update data. In addition, it should allow the practitioner to achieve the fol- lowing: • Construction of the watermarked image, • Storage of the watermarked image, • Verify the integrity of the medical image, • Retrieve patient information from the watermarked image, • Archiving original image. 2.1. Construction of the watermarked image To ensure the integrity of images and confidentiality, we used the technique of watermarking where information and images of the patient are a single entity. The construction of the water- marked image is one of the main functions of our system. It includes the following tasks: • retrieve the original image from database, • separation of the LSB plane 2 of the image (Figure 1), • construction of signature with the moments [6] of the edge map 3 (Figure 2), 2 Least Significant Bits plane: the back plane of the image. 3 map of points representing contour‘s image.