the National Physical Laboratory in the United Kingdom, also thought of the same idea and implemented a trial network. While Baran used the term "message blocks" for his units of communication, Davies used the term "packets," as it was capable of being translated into languages other than English without compromise. He applied the concept to a general-purpose computer network. Davies's key insight came in the realization that computer network traffic was inherently "bursty" with periods of silence, compared with relatively-constant telephone traffic. It was in fact Davies's work on packet switching, not Baran's, that initially caught the attention of the developers of ARPANET at the Symposium on Operating Systems Principles in October 1967. Baran was happy to acknowledge that Davies had come up with the same idea as him independently. In an e-mail to Davies, he wrote: Leonard Kleinrock, a contemporary working on analyzing message flow using queueing theory, developed a theoretical basis for the operation of message switching networks in his proposal for a Ph.D. thesis in 1961-2, published as a book in 1964. In the early 1970s, he applied this theory to model the performance of packet switching networks. However, the representation of Kleinrock's early work as originating the concept of packet switching is disputed by other internet pioneers, including Robert Taylor, Baran and Davies. Baran and Davies are recognized by historians and the U.S. National Inventors Hall of Fame for independently inventing the concept of digital packet switching used in modern computer networking including the Internet. In 1969, when the US Advanced Research Projects Agency (ARPA) started developing the idea of an internetworked set of terminals to share computing resources, the reference materials that they considered included Baran and the RAND Corporation's "On Distributed Communications" volumes. The resiliency of a packet-switched network that uses link-state routing protocols, which are used on the Internet, stems in some part from the research to develop a network that could survive a nuclear attack. Later work In 1968, Baran was a founder of the Institute for the Future and was then involved in other networking technologies developed in Silicon Valley. He wrote on the subject of computer systems and privacy. Baran participated in a review of the NBS proposal for a Data Encryption Standard in 1976, along with Martin Hellman and Whitfield Diffie of Stanford University. In the early 1980s, Baran founded PacketCable, Inc, "to support impulse-pay television channels, locally generated