Guides

One question, one answer, no preamble.

• What is a legal evidence pack for a document?

  A legal evidence pack is a single self-contained bundle holding a document plus everything needed to prove it is what it claims to be: the document itself in an archival format, a cryptographic hash of it, a trusted timestamp, an audit trail of every action taken on it, and a manifest that seals both the individual files and the set as a whole. Its purpose is that a third party can verify it without access to the system that produced it.

• How do I prove a document existed on a certain date?

  To prove a document existed on a certain date, hash the document and send that hash to a trusted Timestamp Authority, which returns a signed token binding the hash to a time it attests to. That token is evidence a third party can check without trusting you. A date in your own file system, database or document metadata is not evidence, because you control it.

• How can I prove a PDF has not been altered?

  To prove a PDF has not been altered, record a cryptographic hash of the file at a known moment, bind that hash to a trusted timestamp from a third party, and keep an auditable record of everything that happened to the document since. The hash detects any change, the timestamp fixes the moment, and the record explains the gap between then and now. PDF/A conformance and file metadata prove none of this on their own.