Long before Wikileaks, Assange worked on a project called "Rubberhose". (A hidden encrypted filesystem designed to offer protection against cryptanalysis by torture.)

http://en.wikipedia.org/wiki/Rubber-hose_cryptanalysis | http://en.wikipedia.org/wiki/Rubberhose_(file_system)

Wired in 2008: "Among other achievements, he [Assange] co-invented Rubberhose deniable encryption, which would let a dissident being tortured reveal one key to unlock a hard drive, while not giving away that there was a second or third password-locked folder of information."

http://www.wired.com/politics/onlinerights/news/2008/07/wiki...

See also: TrueCrypt hidden volumes.