This is what financial cryptography is about (h/t to Jeroen). Copied from Qi of the TheCodelessCode:
Said Bawan: “Chiuyin, the Governor’s treasurer, is blind as an earthworm. A thief may give him a coin of tin, claim that it is silver and receive change. When the treasury is empty, which man is the villain? Speak right and I will spare you all blows for one week. Speak wrong and my staff will fly!”
The novice thought: if I say the thief, Bawan will surely strike me, for it is the treasurer who doles out the coins. But if I say the treasurer he will also strike me, for it is the thief who takes advantage of the situation.
When the pause grew too long, Bawan raised his staff high. Suddenly enlightened, the novice cried out: “The Governor! For who else made this blind man his treasurer?”
Bawan lowered his staff. “And who is the Governor?”
Said the novice: “All who might have cried out ‘this man is blind!’ but failed to notice, or even to examine him.”
Bawan nodded. “This is the first lesson. Too easily we praise Open Source, saying smugly to each other, ‘under ten thousand eyeballs, every bug is laid bare’. Yet when the ten thousand avert their gaze, they are no more useful than the blind man. And now that I have spared you all blows for one week, stand at ease and tell me: what is the second lesson?”
Said the novice: “Surely, I have no idea.”
Bawan promptly struck the novice’s skull with his staff. The boy fell to the floor, unconscious.
As he stepped over the prone body, Bawan remarked: “Code as if everyone is the thief.”Posted by iang at April 20, 2014 10:20 AM | TrackBack