Expectation maximization clustering and sequential pattern mining based approach for detecting intrusive transactions in databases

摘要

Database security is pertinent to every organisation with the onset of increased traffic over large networks especially the internet and increase in usage of cloud based transactions and interactions. Greater exposure of organisations to the cloud implies greater risks for the organisational as well as user data. In this paper, we propose a novel approach towards database intrusion detection systems (DIDS) based on Expectation maximization Clustering and Sequential Pattern Mining (EMSPM). This approach unlike any other does not have records and assumes a predetermined policy to be maintained in an organisational database and can operate seamlessly on databases that follow Role Based Access Control as well as on those which do not conform to any such access control and restrictions. This is achieved by focusing on pre-existing logs for the database and using the Expectation maximization clustering algorithm to allot role profiles according to the database user's activities. These clusters and patterns are then processed into an algorithm that prevents generation of unwanted rules followed by prevention of malicious transactions. Assessment into the accuracy of EMSPM over sets of synthetically generated transactions yielded propitious results with accuracies over 93%.