Sharif Digital Repository

The scope of cyber-crime and related complexity is growing rapidly. Keeping a history of communications and exchanged data for analysis is very important and inevitable. Maintenance of data related to history enables the reconstruction of the events that have happened, but storing everything in raw would require large storage. The highly needed volume for storing these data causes great challenges such as very long time for inserting and searching data. Moreover privacy concerns are another problem in this context, so saving all raw data is not possible.Using methods like compressing and hashing can help in solving such problems. Accordingly, Payload Attribution techniques have been proposed... 

One of the security issues in database outsourcing scenario is the correctness of the query results. Correctness verification includes integrity, completeness and freshness of the results. Most of the proposed approaches for correctness verification impose high overhead on the components of the scenario which prevents the scenario to implemented in practical applications. In this thesis, we have proposed a probabilistic approach which imposes acceptable overhead for correctness verification of returned results of service provider. The approach uses the previous behavior of the service provider to calculate a trust value toward it which is used to adjust the imposed overhead. In other words,...