An audit trail that shows if anyone tried to rewrite history
Who sent it, who opened it, who verified and who signed, with IP addresses and timestamps. Records are chained with SHA-256, so a removed or altered entry breaks the chain.
Append-only, hash-chained log
Each audit entry stores the hash of the previous entry in your organization's chain. Entries are only ever added, never updated or deleted, which the database itself enforces, and each tenant has its own independent chain.
If someone removed or edited a record directly in the database, the chain would no longer verify. Events cover the whole lifecycle, from sign-in and settings changes to sending, viewing and signing.
Signatures linked to each other
Every signature on a document points to the hash of the previous one. Before a document is marked as completed, sign.yt walks the whole chain and refuses to complete it if anything does not match.
A broken chain is recorded in the audit log, so a problem is visible instead of being quietly sealed into a finished PDF. Together with the PAdES signatures this gives two independent ways to prove the order of events.
Explicit consent and a Bitcoin anchor
Before signing, each signer ticks a consent statement. Its text, language and hash are stored with the signature and in the audit log, so you can show exactly what the person agreed to.
When a document is completed, sign.yt anchors the hashes of the signed PDF, the audit trail and the head of the audit chain in Bitcoin through OpenTimestamps. The proof shows the files existed at that block time and can be checked with the open-source ots tool, without relying on sign.yt.
Certificate of completion in the PDF
The signed PDF ends with a certificate of completion: each signer's name, email, role, verification method, when the document was sent, viewed and signed, the IP address and the browser. Your evidence travels with the file.
Because the certificate is part of the PDF, it stays with every copy of the document, wherever it is stored or forwarded. Its QR code and short link open a public verification page for the document.
Find and export what you need
Filter the organization audit log by event type, or download the full history of a single document as CSV for your lawyer or auditor.
The evidence ZIP puts everything in one download: the signed PDF, a standalone audit trail, the OpenTimestamps proof, the platform seal certificate, a manifest of SHA-256 hashes and a README that explains how to verify each part. Signers can download it too.
Entries record the actor, email and IP address, the target and the details of the event. Organization admins see only their own organization, and the log is paginated so even long histories stay fast to browse and search.
Frequently asked questions
Can an audit entry be edited or deleted?
No. The log is append-only, and any change made outside the application breaks the hash chain.
What does the certificate of completion contain?
Signer identity, verification method, timestamps for sending, viewing and signing, IP address and user agent.
Can I export the audit trail?
Yes. Each document's history can be downloaded as CSV, and the full evidence bundle as a ZIP.
What is the Bitcoin anchor?
An OpenTimestamps proof that the document hashes existed when a given Bitcoin block was mined. It is confirmed within hours and can be verified independently of sign.yt.
More features
- GDPR compliance
Data export and erasure requests handled in the product, PDFs encrypted at rest with a separate key per organization, and strict tenant isolation.
- PAdES signatures
Every signer gets a cryptographic PAdES signature in the PDF, plus a final platform seal and a certificate of completion. Any change after signing shows.
- Public verification
Each signed document carries a QR code and short link to a public check page. Masked names, signing dates, seal status and a file comparison.