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ZK Proof Lab

Exhibit 01 · The Ali Baba Cave Protocol

EXHIBIT 01⬡ CONCEPTUAL MODEL
The Ali Baba Cave Protocol
The classic thought experiment — proving knowledge without revealing it · Goldwasser, Micali, Rackoff 1985
✓ Completeness ✓ Soundness ✓ Zero-Knowledge
Repository ZK Primer View Source
Preset: Honest 10 Preset: Bluff Trap
Cryptographic honesty: this exhibit is a conceptual thought experiment to teach the shape of zero-knowledge proofs. It does not claim production-grade cryptographic parameters.

This is the easiest zero-knowledge story to understand: a person goes into a cave, the verifier calls out which side they should come back from, and only someone who knows the secret door word can always do it. If they know the word, they can pass every round.

If they are bluffing, they are just guessing and will be wrong about half the time. The verifier also never learns the secret word, because all they ever see is whether the prover came out on the requested side.

PROVER (inside the cave)
Honest Bluffing
SECRET DOOR ENTRANCE LEFT RIGHT P
Ready.
VERIFIER (outside)
Verifier confidence0.00%
P(cheater passes) = (1/2)0 = 100%
— protocol log —
What the verifier learns: Nothing except that the prover knows the secret. The verifier never sees which path the prover takes — only whether they exit the correct side. Soundness: a cheater succeeds with probability (1/2)^n, collapsing exponentially to zero.