eSignature & Stamp Glossary

Plain-English definitions of eSignature, digital signature, stamp, notarization and document-verification terms.

• Electronic Signature — A digital mark — typed, drawn, or generated — that indicates a signer's intent to be bound by a document.
• Digital Signature — A cryptographic signature using public-key infrastructure (PKI) that mathematically proves authorship and detects any tampering.
• eIDAS — The EU regulation that defines three legal tiers of electronic signature — Simple (SES), Advanced (AdES), and Qualified (QES).
• ESIGN Act — The U.S. federal law (15 U.S.C. § 7001) that gives electronic signatures the same legal effect as handwritten ones.
• UETA — The Uniform Electronic Transactions Act — U.S. state-level law adopted in 49 states giving electronic signatures legal validity.
• Qualified Electronic Signature (QES) — The highest tier of electronic signature under eIDAS — legally equivalent to a handwritten signature in every EU member state.
• Advanced Electronic Signature (AdES) — A middle-tier eIDAS signature that uniquely identifies the signer and detects any later changes to the document.
• Audit Trail — A timestamped, immutable record of every action taken on a document — view, sign, decline, download, share.
• Audit Certificate — A PDF that summarizes every event in a document's audit trail — the legal evidence record for a signed contract.
• KYC (Know Your Customer) — Identity verification — typically ID document upload + selfie liveness check — to confirm a signer is who they claim to be.
• Liveness Check — Anti-spoof technology that confirms a real, live person is present in front of the camera — not a photo, video, or mask.
• PKI (Public Key Infrastructure) — The cryptographic framework — keys, certificates, and authorities — that backs digital signatures and HTTPS.
• Hash (SHA-256) — A one-way function that turns any document into a fixed-length fingerprint — used to detect tampering.
• TSP (Trust Service Provider) — An EU-recognized organization that issues digital certificates and timestamp tokens used in Advanced and Qualified eSignatures.
• eSignature vs Digital Signature — eSignature is the broad legal category; digital signature is a specific cryptographic technique within it.
• Envelope — A container for a document (or set of documents) plus its signers, routing rules, and signing status.
• Signing Order — The rule that controls when each signer is unlocked — all at once (parallel) or one after another (sequential).
• Signer — A party invited to sign a document, identified by name, email or phone, and the role they're signing as.
• Tamper-Evident — A property where any post-signing change to a document is immediately detectable through a hash mismatch.
• Witness — A third party who observes a signing and signs the document themselves to attest that the signer's consent was given knowingly.
• Notary / Notarization — A formal certification by a public officer that a signer's identity is verified and the document was executed willingly.
• AML (Anti-Money Laundering) — Regulations and screening designed to prevent financial systems from being used to launder illicit funds.
• GDPR — The EU's data-protection regulation governing how personal data is collected, processed, stored, and erased.
• DPA (Data Processing Agreement) — A contract between a data controller and a data processor required by GDPR Article 28.
• Data Residency — Where customer data is physically stored — a compliance requirement in many jurisdictions.
• In-Person Signing — A flow where the signer signs on the document owner's device — typically in a retail, lender, or sales meeting.
• OTP (One-Time Password) — A short numeric code sent via SMS, WhatsApp, or email that the signer enters to authenticate before signing.
• Two-Factor Authentication (2FA) — An identity check that requires two independent factors — typically a password plus a code from a phone or app.
• eStamp — A digital replacement for a physical company stamp — overlaid on a signed document for visual authority.
• Company Seal — A company's official mark — historically embossed, now applied digitally — that signifies the organisation has formally executed a document.
• Official Seal — A formal seal applied by an authority or organisation to certify that a document is authentic and officially issued.
• Digital Stamp — An electronic stamp applied to a document online — replacing a physical rubber stamp with a verifiable, reusable mark.
• Rubber Stamp — The classic ink-on-paper stamp — and how to replace it with a digital rubber stamp you can apply to PDFs online.
• Approval Stamp — A stamp — typically "APPROVED" — applied to mark that a document has passed review and is authorised to proceed.
• Certified True Copy — A copy of a document stamped and signed to certify it is a faithful, unaltered reproduction of the original.
• Notary Stamp — The official seal a notary public applies to attest they witnessed a signing or certified a document.
• Stamp Verification — Confirming that a stamp on a document is genuine, current, and not revoked — usually by scanning its QR code or visiting its verification link.
• Document Fraud — Forging, altering, or falsely presenting a document — prevented by cryptographic sealing and public verification.
• Tamper-Evident Seal — A cryptographic seal that makes any change to a document detectable after it is signed.