A method and apparatus facilitates the prevention of interception of incoming data, such as keystroke data in the form of a message to an application, by inserting application generated random insertion data into a message stream. A feedback input circuit is coupled to an output of the power converter for generating a feedback signal. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key. The logical rules can include social security rules, geography rules, and address ranking rules.