The latest version of the specification is version v2.

Digital proof Experimental

  1. Register proof
  2. Consistency proof
  3. Entry proof
  4. Root hash
  5. Signed tree head
  6. Audit path

Register proof

A register proof is a digitally-signed demonstration of the integrity of all entries in a register. Given a register proof, it is possible to verify that all of the entries and blobs are correct, and that the entries are in the correct order.

Consistency proof

A consistency proof proves the append-only property of a register.

The consistency proof for a register containing m entries and a previous version of the same register containing n entries is the information required to prove that the first n entries are equal for both, given a Register proof for each version of the register.

A consistency proof does not require to get the entirety of either logs to verify the consistency between the two.

Entry proof

An entry proof is the information required to prove the integrity of a single entry within a register of a given log size, given a Register proof.

An entry proof does not require a client to get the entire register to verify the integrity of a single entry.

Root hash

The root hash for a register is the Merkle tree root hash (RFC6962 section 2.1) of a Merkle tree containing all entries in the register.

Signed tree head

The signed tree head for a register is the signed Merkle tree root hash (RFC6962 section 2.1) of a Merkle tree containing all entries in the register.

Audit path

The audit path provides the shortest list of additional nodes in the Merkle tree required to compute the Merkle tree root hash.

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