Baran, Paul. “On distributed communications.” Volumes I-XI, RAND Corporation Research Documents, August (1964): 637-648.
Entry by Samuel Stone
In this memorandum, Paul Baran, a RAND Corporation researcher, proposes a new system for an American communications system, very similar to the modern Internet, as part of his research with the RAND Corporation. As was typical of RAND Corporation research, Baran’s network proposal had primarily military applications. In the introduction of the document, he explains that his memorandum is “directed toward examining the use of redundancy as one means of building communications systems to withstand heavy enemy attacks” (iii). The primary impetus behind his research seems to have been developing a system that would allow American military personnel to continue communicating in the aftermath of a nuclear attack that destroyed of the physical components of a network.
In order to accomplish the goal of creating a network that is less vulnerable to physical destruction, Baran proposes a distributed network, or one in which there are no “central nodes” that could be destroyed to sever the network. Much of the document is focused on analysis about the probability of network destruction based on physical destruction of network nodes in a distributed network like the one that he suggests. He explains, for example, that “bisect[ing] a 32-link network requires direction of 288 weapons each with a probability of kill, pk = 0.5” (6).
In addition to addressing concerns of how the proposed network could withstand physical attack, Baran explains the security mechanisms that the network will utilize to ensure that its transmissions remain inaccessible to the general public: “[T]he mechanism within the proposed system…takes a channel or message and chops it into small pieces (like a fruit salad), transmitting it on as a series of message blocks, each using a different path…unclassified material is [also] purposely transmitted cryptographically” (8). This system of breaking data into smaller “message blocks” and sending the blocks individually explains modern-day packet switching, the method by which information is transmitted across the Internet today.
As Baran later explains, nodes in the distributed network will use cryptography to ensure that information being passed from computer-to-computer is already encrypted, and the fact that these “blocks” or packets of data will travel via semi-random paths will make it “impossible to decrypt a stream of Message Blocks…unless the interceptor records all outgoing links from the Switching Nodes for a single Multiplexing Station and has all keys, he will not be able to decrypt the sequence of Message Blocks” (26). The network that Baran proposes has multiple levels of security measures in place to attempt to prevent a malicious user from intercepting any communications that travel through the network.
This source is particularly significant because it illustrates many of the principles upon which the modern Internet was founded. Although the Internet has become a vastly important marketplace and communication method for civilians, much of the infrastructure that allows it to operate is based on the militaristic principles that Baran outlined in this report for the RAND Corporation. The same decentralization of the Internet that now allows companies to house storage facilities in remote complexes while sending signals across the globe was originally designed to create a system of communication that would be resistant to attack. Additionally, a server going down at one company or in one location does not cause the entire Internet to stop functioning; the redundancy of Baran’s individual “nodes” or the modern Internet’s individual servers prevents any disaster from causing widespread Internet failures.
Furthermore, the encryption methods and packet-switching mechanisms that allow financial institutions and other businesses with security needs to safely transmit information through wires without worrying about the potential of data interception were initially designed to allow the military to safely share classified information without risk of interception by the Soviet Union or other anti-American parties.
In general, the fact that the Internet was designed with military applications in mind helped create much of the necessary framework to allow it to function in the way that it does today. Although Paul Baran likely had no conception of the enormous scale that the Internet would eventually take on, his ingenuity in conceptualizing its back-end infrastructure in a way that would allow for both continuity and security certainly helped lead to its successful implementation in today’s world.
Like many aspects of science developed during the Cold War, primarily military applications led to the creation of new technology, and the civilian population eventually developed new uses for it. Without Baran’s distributed network solution, the modern Internet may not have developed such a resilient infrastructure, and without military need for a secure network, modern corporations might never have been able to develop such a system. Baran’s work, despite its militaristic intentions, was instrumental in creating the Internet as the world knows it today.
Science in the Cold War 