Foundations of Blockchain

General examples

Let's look at the zero-knowledge proof system with few examples.

A card trickster

Let's consider an example of a card trickster who claims that they know a trick where they can predict any card that was guessed by the spectator. In this example, the trickster is the prover, the spectator is the verifier, and the magic trick is the secret knowledge. The only way to prove that they know the trick is by performing the act. The trickster asks the spectator to think of a card. After the spectator thinks of a card, the trickster waves the magic wand and takes out a card. The spectator confirms that it was the chosen card, and they now believes that the trickster knows the trick. If the spectator still needs to confirm it, they ...