Electronic vs. Digital Signature: What's the Difference?

The short answer

Every digital signature is a kind of electronic signature, but most electronic signatures are not digital signatures. Think of “electronic signature” as the category and “digital signature” as one particular, more technical way of making one.

What is an electronic signature?

The federal ESIGN Act defines it this way:

“The term ‘electronic signature’ means an electronic sound, symbol, or process, attached to or logically associated with a contract or other record and executed or adopted by a person with the intent to sign the record.”

15 U.S.C. § 7006(5) · Official source

That covers a lot: a signature drawn with your finger on a phone, a typed name at the end of a form, a scanned image of your handwritten signature, checking a box that says “I agree,” even a recorded “yes” on a phone line. What makes it a signature is the intent to sign, not the technology.

Electronic signature services like MultiDocs, DocuSign or Dropbox Sign add something important on top: an audit trail that records how the signer was reached, when they opened and signed the document, and from which device and IP address.

What is a digital signature?

A digital signature is a mathematical technique, standardized in the US by NIST in FIPS 186-5. In plain terms:

1. The software calculates a hash of the document: a short fingerprint (for example with SHA-256) that changes completely if a single character changes.
2. The signer's private key is used to sign that fingerprint. The key belongs to a digital certificate, usually issued by a certificate authority that has checked the signer's identity.
3. Anyone can use the matching public key to confirm the fingerprint, which proves the document hasn't changed and that it was signed with that certificate.

You'll see this in PDF readers as a blue ribbon or a “Signed and all signatures are valid” banner. It's strong protection against tampering, but it needs certificates, which cost money and take setup.

Side by side

What US law says

The US took a technology-neutral approach. The ESIGN Act (2000) says a signature, contract or record “may not be denied legal effect, validity, or enforceability solely because it is in electronic form” (15 U.S.C. § 7001(a)). It doesn't require certificates, encryption or any particular method. The Uniform Electronic Transactions Act (UETA), adopted by 49 states plus D.C., Puerto Rico and the U.S. Virgin Islands, does the same at state level. New York has its own law, the Electronic Signatures and Records Act, with the same effect for most documents.

Some other countries rank signatures in levels and give certificate-based signatures special status. US law has no such ladder: an electronic signature is an electronic signature, and in a dispute the question is evidence. More in the ESIGN Act explained and the UETA explained.

When you actually need a digital signature

Rarely, for everyday business. Situations where a certificate-based signature may be required:

• Some government filings and agencies that publish their own technical rules. For example, FDA rules (21 CFR Part 11) set strict controls for electronic signatures in regulated companies, though they don’t always require a certificate.
• Documents where the other side insists on it, often large companies or public bodies with their own signing policy.
• Professional seals in some states, such as engineers or architects stamping plans, where licensing boards set the method.
• Cross-border deals when the other party's country requires a certificate-based signature.

If nobody has asked you for a certificate, you almost certainly don't need one. For leases, NDAs, estimates, offer letters, permission slips and waivers, an electronic signature with an audit trail is the norm.

How an electronic signature is proven

Courts look at whether the signature can be attributed to the person. UETA says a signature is attributable to a person “if it was the act of the person,” which can be shown “in any manner,” including the security procedure used. In practice, that means a record of: the email or phone number the signing link was sent to, the IP address and device it was opened on, the date and time of each step, and proof that the document wasn't changed afterward. A good audit trail does most of what people want from a digital signature, without asking signers to buy a certificate.

What MultiDocs uses

To be clear: MultiDocs creates standard electronic signatures, not certificate-based digital signatures. Every signed document gets a certificate of completion on its last page with the date and time, the email or phone the link was sent to, the IP address, device and browser, a unique signer code and the SHA-256 fingerprint of the document. We keep that fingerprint so anyone can upload the PDF at /verify and confirm it's exactly the document that was signed. If your situation needs a certificate-based signature, use a tool built for that.