Efficient implementation of cryptographically useful "large" Boolean functions Cryptography provides the necessary tools for accomplishing private and authenticated communication and for performing secure and authenticated transactions over the Internet as well as other networks. It is highly probable that every single bit of information flowing through our networks will have to be either encrypted or signed and authenticated in a few years from now. Historically, four groups of people have used and contributed to the art of cryptography: The military, the diplomatic corps, diarists, and lovers. Of these, the military has had the most important role and has shaped the field. Within military organizations, the messages to be encrypted have traditionally been given to poorly paid clerks for encryption and transmission. Until the advent of computers, one of the main constraints on cryptography had been the ability of the code clerk to perform the necessary transformations, often on a battlefield with little equipment. An additional constraint has been the difficulty in switching over quickly from one cryptographic method to another one, since this entails retraining a large number of people. Modern cryptography is based on key, denoted by K. This key might be any one of a large number of values. The range of possible values of the key is called the keyspace. Both the encryption and decryption operations use this key, so the functions are given as: Ek(M)=C Dk(C)=M where M is the message and C is ciphertext. A message is nothing but plaintext. The process of disguising a message in such a way as to hide its substance is encryption. An encrypted message is ciphertext. The purpose of turning cipher text back into plaintext is decryption. Home Networking The latest advances in the Internet access technologies, the dropping of PC rates, and the proliferation of smart devices in the house, have dramatically increased the number of intelligent devices in the consumer's premises. The consumer electronics equipment manufacturers are building more and more intelligence into their products enabling those devices to be networked into clusters that can be controlled remotely. Advances in the Wireless communication technologies have introduced a variety of wireless devices, like PDAs, Web Pads, into the house. Advent of multiple PCs and smart devices into the house, and the availability of high-speed broadband Internet access, have resulted in in-house networking needs to meet the following requirements of the consumers: " Simultaneous internet access to multiple home users " Sharing of peripherals and files " Home Control/Automation " Multi-player Gaming " Connect to/from the workplace " Remote Monitoring/Security " Distributed Video The home networking requirement introduces into the market a new breed of products called Residential Gateways. A Residential Gateway (RG) will provide the necessary connectivity features to enable the consumer to exploit the advantages of a networked home. The RG will also provide the framework for Residential Connectivity Based Services to reach the home. Examples of such Residential Connectivity Based Services include: Video on Demand, IP Telephony, Home Security & Surveillance, Remote Home Appliance Repair & Trouble shooting, Utility/Meter Reading, Virtual Private Network Connectivity and Innovative E-commerce solutions.