Abstract: There are disclosed techniques for use in providing security in a computer network. In one embodiment, the techniques comprise a method including multiple steps. The method comprises receiving user access data characterizing user access with a protected resource within a computer network. The method also comprises evaluating the user access data to extract information therefrom that describes user access with respect to a feature of user access. The method also comprises determining a cardinality value in connection with the feature based on the extracted information and a maximum cardinality threshold. It should be appreciated that the cardinality value is limited by the maximum cardinality threshold such that the cardinality value cannot exceed the maximum cardinality threshold. The method also comprises presenting the cardinality value for facilitating fraud detection.

Abstract: Sequences of discrete events, such as clicks on a website, are evaluated for periodic behavior, a period is calculated, and the sequence is scored to determine the confidence that the sequence really exhibits periodicity. The random variations on the timing of the discrete events due to transmission delays or other factors may be reduced or eliminated from the evaluation. An apparatus for performing the method of evaluation may include a computer programmed to carry out the method.

Abstract: A method is provided to estimate statistics of user interaction with a computing system. For example, the method includes tracking the interaction of a plurality of users with the computing system to collect statistical data associated with the user interaction, wherein the statistical data is collected in each of a plurality of sampling intervals. The collected statistical data is applied to a digital linear recursive filter that is configured to combine and filter the collected statistical data based on at least one cyclical function. The filtered statistical data generated by the digital linear recursive filter is then utilized to compute final statistics indicative of the user interaction with the computing system. The final statistics are utilized to identify anomalous activity involving the computing system.