Audit Trails and Completion Certificates

A signature is only as trustworthy as the record behind it. StretchContracts captures every action on an envelope in a tamper-evident audit trail and, when signing completes, produces a sealed completion certificate that ties the signed document to that trail. This article explains what's recorded, how integrity is protected, and how to read a certificate.

What gets recorded

Every meaningful action on an envelope becomes an audit event, including:

• Created — the envelope, each recipient, and each field being added.
• Sent — the envelope going out for signature.
• Viewed — a recipient opening their signing session (including failed access-code attempts).
• Consent given — a signer agreeing to sign electronically, with the consent-text version.
• Signed — a recipient completing and submitting their fields.
• Declined — a recipient refusing, with any reason given.
• Voided — the sender cancelling the envelope, with a reason.
• Completed — the final event when all required signers have signed, referencing the completion certificate.

Each event captures who acted, when, their IP address and browser, and the relevant details.

How the trail is tamper-evident

The audit trail is a hash chain. Each event is sequentially numbered and cryptographically linked to the one before it: every event carries a hash computed from its own contents plus the previous event's hash. This means:

• Events must appear in an unbroken sequence (no gaps).
• Each event's link to the previous event must match.
• Each event's own hash must be valid.

If anyone altered, inserted, or removed an event, the chain would no longer verify — the mismatch would be detectable. StretchContracts checks this integrity whenever it presents an envelope, so a trail that verifies is a trail you can trust.

The completion certificate

When the last required signer submits, StretchContracts automatically seals a completion certificate. The certificate binds together:

• A document fingerprint — a cryptographic hash of the signed document's content (the envelope, its recipients and their signing status, and every field value).
• The audit root hash — the hash of the final event in the chain, which by the chain property fixes the entire history.
• Completion details — the envelope and contract key, the completion time, and how many recipients signed.
• A cryptographic seal — a signature over all of the above, so the certificate itself can be verified and can't be forged or altered after the fact.

Because the certificate ties the document fingerprint to the audit root, it proves this exact document was signed via this exact, unbroken sequence of events.

Step-by-step: verify a completed signature

1. Open the completed envelope.
2. Review the audit trail — the full ordered list of events with actors, times, and IP/browser details.
3. Confirm the integrity check passes (the chain verifies with no gaps or mismatches).
4. Open the completion certificate and confirm its seal is valid and its document fingerprint and audit root are present.

A realistic example

After a dispute months later, Elena needs to prove a vendor signed a specific SOW. She opens the completed envelope. The audit trail shows the vendor's contact viewing the document on March 3 at 14:22 from their IP, consenting to electronic signature, then signing three minutes later — followed by the automatic completion event. The integrity check verifies with no gaps. The completion certificate's document fingerprint matches the signed content and its audit root matches the last event. Elena exports this record as her proof: not just "they signed," but a cryptographically sealed chain of exactly what happened and when.

Tips

• The audit trail is your evidence. Treat a completed envelope's trail and certificate as the authoritative record of the signing — more reliable than an email thread.
• Failed access-code attempts are logged too. If someone repeatedly failed to open a session, you'll see it — useful for spotting the wrong recipient or a delivery problem.
• Don't alter completed records. They're sealed by design; any tampering would break verification and undermine your own evidence.
• Keep the contract key handy. The certificate references it, tying the signature back to the agreement record.

FAQ

Can the audit trail be edited? No. It's append-only and hash-chained; edits would break the integrity check and be detectable.

What is the "audit root hash"? It's the hash of the last event in the chain. Because each event depends on the previous one, that single value effectively fixes the entire history.

What does the completion certificate prove? That a specific document (by fingerprint) was signed through a specific, verified sequence of events, sealed cryptographically so it can't be forged or altered afterward.

Is a PDF of the signed document available to download? StretchContracts focuses on the sealed record and certificate; downloadable PDF export is not currently enabled. The verifiable envelope, audit trail, and certificate are your authoritative record.