DESIGN AND DEVELOPMENT OF KEY REPRESENTATIONAUDITING SCHEME FOR SECURE ONLINE AND DYNAMICSTATISTICAL DATABASES
Elshiekh Mohammed Ahmed, Asim Abdallah · UTPedia (Universiti Teknologi Petronas) · 2010
A statistical database (SDB) publishes statistical queries (such as sum, average, count, etc.) on subsets of records. Sometimes by stitching the answers of some statistics, a malicious user (snooper) may be able to deduce confidential information about some individuals. When a user submits a query to statistical database, the difficult problem is how to decide whether the query is answerable or not; to make a decision, past queries must be taken into account, which is called SDB auditing. One of the major drawbacks of the auditing, however, is its excessive CPU time and storage requirements to find and retrieve the relevant records from the SDB. The key representation auditing scheme (KRAS) is proposed to guarantee the security of online and dynamic SDBs. The core idea is to convert the original database into a key representation database (KRDB), also this scheme involves converting each new user query from a string representation into a key representation query (KRQ) and storing it in the Audit Query table (AQ table). Three audit stages are proposed to repel the attacks of the snooper to the confidentiality of the individuals. Also, efficient algorithms for these stages are presented, namely the First Stage Algorithm (FSA), the Second Stage Algorithm (SSA) and the Third Stage Algorithm (TSA). These algorithms enable the key representation auditor (KRA) to conveniently specify the illegal queries which could lead to disclosing the SDB. A comparative study is made between the new scheme and the existing methods, namely a cost estimation and a statistical analysis are performed, and it illustrates the savings in block accesses (CPU time) and storage space that are attainable when a KRDB is used. Finally, an implementation of the new scheme is performed and all the components of the proposed system are discussed.