Knowledge Base

Overview

A proof bundle is the single self-contained file you download when you timestamp something with Truestamp. It carries the subject’s data and its system-generated metadata, the Merkle inclusion proofs, an Ed25519 signature, and the public-blockchain commitment records needed for offline verification without contacting any Truestamp server. It serializes to two interchangeable encodings, human-readable JSON and compact binary CBOR, and a top-level type key names the kind of subject it is about (item, block, beacon, or one of the three entropy sources), with the matching frozen t type code bound into the signed payload. A bundle must contain at least one public-chain commitment, so one can only be generated once the subject’s block has been committed.

Two properties are worth stating plainly, because they are what make a bundle stand alone.

• Nothing in a bundle is opaque. Every hash a verifier needs is recomputed from bytes the file carries, the subject and block metadata maps included. There is no field a reader has to accept on trust because it cannot be checked.
• A bundle may carry its witnesses. A downloaded file for an item names the head block and the entropy records the submission committed to, and carries each one in full, so the submitted-after edge can be confirmed from the file plus the public sources rather than from Truestamp. A compact variant leaves the witness detail out; the fingerprint, the signature, and every other check are unaffected.

The field-by-field reference is the proof bundle wire format; checking a bundle is covered in verify a proof, and the path from submission to a downloadable bundle is the proof lifecycle.