Digital Certificate (Signing Certificate)

A signing certificate serves as tamper-proof evidence that a document was signed by specific parties at specific times. It typically includes:

- **Document hash** (e.g., SHA-256) — a cryptographic fingerprint of the document content - **Timestamps** — when each party signed - **IP addresses** — from where each party signed - **Verification methods** — how each party's identity was confirmed (email OTP, API key, etc.)

If any byte of the document is modified after signing, the hash changes and the certificate becomes invalid. This is how tamper detection works.

Signbee appends a certificate page to every signed PDF containing a SHA-256 hash, timestamps, IP addresses, and verification methods for both parties.