Abstract: A method and system for testing a plurality of filter rules in a computer system is disclosed. The plurality of filter rules is used with a key. Each of the plurality of filter rules is capable of being described using a plurality of bits corresponding to a portion of the key. The plurality of bits can include at least one binary value, at least one wildcard, and at least one boundary symbol. The at least one binary value can be a zero or a one. The method and system include selecting a portion of the plurality of filter rules that the key can match by testing part of the key against a portion of the plurality of bits and explicitly testing the key against the portion of the plurality of filter rules. A first bit of the portion of the plurality of bits has a first maximum number of the at least one binary symbol for the plurality of filter rules.