This month John Kiriakou was released from prison, and he's currently serving the final three months of his 2.5-year sentence under house arrest in Virginia.
The 50-year-old father-of-five left the CIA in 2004, but disclosed details about the intelligence agency's detention and interrogation programme three years later in an interview with ABC News.
But he wasn't arrested until 2012, when he was charged with espionage for revealing the name of one of the CIA employees involved in the programme to a New York Times reporter, who never published the worker's identity.
In a phone interview after his release from prison, Kiriakou told the website Fusion that he had experienced a "terrible three years, and it's ruined me financially and personally".
He remained defiant, however:
But in the greater picture it's all been worth it. I'm proud I had a role in seeing that torture is now banned in the United States.
But despite the report, which said the programme was much more brutal than ever previously acknowledged, former US vice-president Dick Cheney has insisted, on torture and waterboarding, that he "would do it again in a minute".
In response, Kiriakiou told Fusion:
When [these people's] obituaries are written it will say that they were instrumental in the torture programs, and they are desperate to show that it was necessary and it was appropriate, even though it was not necessary, and it was inappropriate.
No matter how many times Dick Cheney says it, it doesn't make it true.
Kirakiou is currently writing a book about the conditions he and other inmates encountered in prison.