A search engine system is disclosed that can include at least one content addressable memory device arranged in a cascade configuration with at least one memory device, such as a static random access memory. The memory system allows the architecture for an IP processor that may provide capabilities to transport and process Internet Protocol packets from Layer 2 through transport protocol layer and may also perform packet inspection through Layer 7. The system also includes valves controlled by an electronic unit. The input interface is connected to a decryption circuit whereby the only manner of providing the common keys to the circuit are in encrypted form encrypted according to the secret key. Further signal processing then completes placing the digital video signal output by the second converter in a format acceptable to standard lower definition digital decoders. The simulator is constrained by predetermined criteria to visit states that meet the criteria thus preserving computer resources.