The US Naval Research Laboratory’s Role in Tor

The United States Naval Research Laboratory (NRL) played a foundational role in the creation of Tor by inventing the underlying technology known as onion routing in the mid-1990s. Originally designed to protect sensitive military and intelligence communications from surveillance, the NRL conceived the cryptographic framework, built the earliest working prototypes, and later collaborated with external computer scientists to develop the open-source network recognized today as Tor.

The Invention of Onion Routing

In the 1990s, the US military recognized a growing vulnerability in internet communication: even if message contents were encrypted, adversaries could still track the metadata—specifically, who was talking to whom, when, and from where. To eliminate this vulnerability, NRL mathematicians and computer scientists Paul Syverson, Michael G. Reed, and David Goldschlag invented “onion routing” in 1995.

The concept relied on wrapping data in multiple layers of encryption—resembling the layers of an onion—and passing it through a series of intermediate network nodes. Each node unpeeled a single layer to discover only the next destination, ensuring that no single computer in the chain ever knew both the origin and the final destination of the data packet.

Developing the First Prototypes

Following the theoretical design, the NRL created the first working demonstrations of onion routing between 1996 and 1997. During this phase, the laboratory tested early proxy systems that allowed users to browse the web anonymously. The NRL team published foundational academic papers explaining how layered encryption and distributed routing could resist traffic analysis and eavesdropping on public networks.

The Evolution into Tor

By the early 2000s, the NRL sought to refine the technology into a scalable, production-ready system. Paul Syverson collaborated with Massachusetts Institute of Technology (MIT) graduates Roger Dingledine and Nick Mathewson to redesign the architecture.

With backing from the NRL and the Defense Advanced Research Projects Agency (DARPA), this collaboration produced the second-generation onion routing system, officially named “The Onion Routing” project, or Tor. The initial alpha version of the Tor network was deployed in October 2002.

The Decision to Make Tor Public

The NRL understood a fundamental principle of anonymity: an intelligence agency cannot hide its communications on a private network. If only government operatives used onion routing, any traffic entering or leaving the system could easily be attributed to the US government.

To create genuine cover traffic, the NRL supported the decision to release Tor’s source code under a free and open-source software license in 2004. By inviting civilian, corporate, and international users to route traffic through the network, the NRL ensured that government communication remained indistinguishable from everyday internet traffic.

Through its pioneering research, initial funding, and strategic open-sourcing, the US Naval Research Laboratory transformed onion routing from an internal defense concept into the world’s most widely used anonymity network.