Tor, the world's largest and most well-known "onion router" network, offers a degree of anonymity that has made it a popular tool of journalists, dissidents, and everyday Internet users who are trying to avoid government or corporate censorship.

But one thing that it doesn't offer is speed—its complex encrypted "circuits" bring Web browsing and other tasks to a crawl. That means that users seeking to move larger amounts of data have had to rely on virtual private networks—which while they are anonymous, are much less protected than Tor. A group of researchers may have found a new balance between privacy and performance.