Cryptography captures a class of social technologies for verifiably demonstrating specific, well-defined properties about information and how it is communicated. Key exchange equips us with secure channels. Digital signatures and their exotic variants give us various forms of attestation. Basic encryption implicitly does the same, but in a privacy preserving manner. When fully homomorphic, it additionally unlocks arbitrary computation on the hidden information. And succinct arguments of knowledge are tools for efficient and powerful persuasion that we possess information to tractably witness the validity of arbitrary statements.
While the mathematics is deep, the details inaccessible, and the security proofs tedious, the fundamental way in which cryptography manages all of these diverse but mutually sympathetic tasks is by algorithmically generating and evaluating evidence. A group signature is evidence of attestation on behalf of an authority; a Merkle authentication path is evidence of membership for an element in a particular set; a range proof is evidence that a value lives in some interval, and so on. Increasingly expressive cryptography allows the production of evidence for increasingly complex claims.
Resilient social institutions are composed of processes that are secured by the production, delivery, and evaluation of high-quality evidence. At their best, peer review and justice systems are such institutions. To the extent that they break down, they do so because evidence is either improperly produced (e.g., experimental falsification), improperly obtained (e.g., “fruit of the poisoned tree”) or improperly evaluated (e.g., misinterpretation of data). Cryptographically generated evidence distributed via smart contracts suffers from none of these frailties.
To build persistent social institutions on-chain, crypto must enable its participants to efficiently coordinate eclectic forms of evidence.
