Electronic Signature vs. Digital Signature

People use the two terms as if they meant the same thing. They don't, and the difference matters when a client, a court or a regulator asks how a document was signed.

An electronic signature is any electronic way of showing you agree to a document: a typed name, a signature drawn with a finger, or ticking a box and clicking Sign. A digital signature is one specific technology for doing that, based on cryptography and certificates. Every digital signature is an electronic signature, but most electronic signatures are not digital signatures.

Electronic signatures: intent plus a record

What makes an electronic signature hold up is mostly not the image of the signature. It is the record around it: who was sent the document, at which email address, when they opened it, that they agreed to sign electronically, when they signed, and from which device and IP address.

In the United States, the ESIGN Act and the Uniform Electronic Transactions Act (UETA) are technology-neutral: an electronic signature generally has the same legal effect as a handwritten one, without requiring any particular technology. Many other countries take a similar approach for everyday business documents.

Digital signatures: certificates and cryptography

A digital signature uses public-key cryptography. The signer holds a private key, usually tied to a certificate issued by a certificate authority that has checked their identity. Signing produces a cryptographic value bound to the exact bytes of the document, so anyone with the matching public key can verify who signed and that nothing changed afterwards. PDF readers such as Adobe Acrobat show this as a signature panel with the certificate details.

Digital signatures are what certain regulated processes require. In the European Union, the eIDAS regulation defines three levels: simple, advanced and qualified electronic signatures. A qualified electronic signature needs a qualified certificate and a qualified signature-creation device, and it has the same legal effect as a handwritten signature across the EU.

Which one do you need?

• •Engagement letters, leases, intake forms, consent forms, quotes and most everyday business agreements: an electronic signature with a good audit trail is what most small businesses use.
• •A process or counterparty that specifically asks for a certificate-based digital signature, an EU advanced or qualified signature, or a notarized document: you need a provider that issues those, and sometimes an in-person or video identity check.
• •Wills, certain court filings and some real-estate or government documents: these can have special signing or witnessing rules. Check the rules that apply to you before signing them electronically.

What Tarchos Sign provides

Tarchos Sign provides electronic signatures, not certificate-based digital signatures. Each signer opens a secure link, agrees to sign electronically and draws or types their signature. When everyone has signed, the completed PDF gets a certificate of completion listing each signer's name, email, IP address, device and signing time, and when they agreed to sign electronically. A SHA-256 fingerprint of the finished file is kept in the document's audit trail, so a later copy can be checked against it.

It does not issue signer certificates or produce eIDAS advanced or qualified signatures. If your document needs one of those, use a qualified trust service provider for that document.

This article is general information, not legal advice.