The actor made the comments to the BBC in an interview celebrating his return to the series in five-part audio adventure Doctor Who: Hornets' Nest.
When asked what makes fans of the programme different, he replied: "Their unswerving loyalty. Their good taste. Their BLIND LOVE.
"The formula is so good. Benevolent alien, a being with secrets. A sonic screwdriver, but I'm sworn to secrecy by the BBC. They pay me 30 pieces of silver every month to be discreet."
Regarding his return to the show, he added: "The scripts arrived at a good moment. I'm a bit capricious about what I accept.
"I asked some hard questions and made some impossible demands. The BBC agreed to everything I asked on condition the details would be locked in a strongbox in the Bank of England.
"They will be revealed on the BBC website on January 20, 2034 at 6.12am - the 100th anniversary of my birth."
Baker's 'Do I Have The Right?' scene from series 12's 'Genesis Of The Daleks' was recently named the best Fourth Doctor TV scene, winning the poll with 32% of votes cast.