Electronic Signature vs Digital Signature: Legal Validity, How They Work, and When to Use Each

You Drew a Signature and Pasted It Into a Contract — Does That Actually Count?

More and more contracts are completed entirely online — employment agreements, lease contracts, service agreements. Many people create a signature image and insert it into a Word document or PDF, then send it off.

But there's always a nagging question: is a contract signed this way legally valid? What happens if the other party disputes it?

To answer that, you first need to untangle a concept most people confuse: electronic signature ≠ digital signature.

Electronic Signature vs Digital Signature: Not the Same Thing

These two terms are used interchangeably everywhere, but they mean completely different things.

Electronic Signature is a legal concept — a broad term for any electronic method attached to a document to express the intent to sign. The range is wide:

• Drawing a signature with your finger on a touchscreen
• Pasting a signature image into a Word document
• Typing your name at the bottom of an email
• Clicking an "I Agree" button
• Completing an action after identity verification via SMS code

All of these are technically electronic signatures.

Digital Signature is a technical concept — specifically a cryptographic signature generated using asymmetric encryption algorithms (RSA, ECDSA, etc.). Here's how it works:

1. Hash the document content to produce a digest
2. Encrypt the digest with the signer's private key, producing the signature value
3. To verify, decrypt the signature with the corresponding public key and check whether the digest matches

A digital signature simultaneously proves two things: who signed the document (identity authentication) and whether the document was altered after signing (integrity verification). A pasted image signature can do neither.

In short: a digital signature is one specific implementation of an electronic signature — and the most secure one. Not all electronic signatures use digital signature technology.

Are Electronic Signatures Legally Valid?

Yes — but with conditions.

In the US, the ESIGN Act (2000) and UETA (Uniform Electronic Transactions Act) establish that electronic signatures carry the same legal weight as handwritten signatures for most contracts. The EU's eIDAS Regulation does the same across member states, defining three tiers: Simple Electronic Signatures, Advanced Electronic Signatures (AES), and Qualified Electronic Signatures (QES).

The general legal requirements for a valid electronic signature come down to two things:

1. The signature can be attributed to the signer (it's clear who signed)
2. Changes to the document after signing can be detected

The problem with image signatures: any image file can be copied and pasted by anyone — there's no way to prove the signer actually performed the action. And if the document content is modified after the image is inserted, the signature image won't show any change. This makes disputes very difficult to resolve.

When is an image signature low-risk? Everyday informal scenarios: internal approval workflows, non-critical agreements between trusted parties. For contracts with significant financial or legal consequences, use a qualified electronic signature platform (DocuSign, Adobe Acrobat Sign, HelloSign) that issues legally binding signatures backed by digital certificates.

Certain document types are explicitly excluded from electronic signing in most jurisdictions:

• Wills, trusts, and testamentary documents
• Court orders and official court documents
• Notices of cancellation for utilities or essential services
• Real estate transactions (varies by jurisdiction)
• Adoption, divorce, and certain family law documents

How to Insert a Signature Image Into Documents Properly

Image signatures remain extremely common in practice. Doing it correctly matters:

Into a Word Document

1. Generate a transparent-background PNG signature using a signature tool
2. In Word, insert the image and set text wrapping to "In Front of Text"
3. Resize and position it over the signature line
4. To prevent modification, save the document as a PDF after inserting the signature

Into a PDF

• Adobe Acrobat: Open PDF → Tools → Fill & Sign → Add Signature
• Online PDF editors: Upload the PDF, insert a signature image
• Sign in Word first, then export to PDF: The signature is embedded as an image during conversion

Making Your Signature Harder to Misuse

• Export as a transparent PNG, not a white-background JPG — it avoids covering document text and looks more like a genuine handwritten signature
• Write the date next to your signature manually, binding the signature to a specific point in time
• For important documents, send via encrypted email or keep a screenshot record after signing

If you need to create a signature image, the Online Electronic Signature Maker on toolshu.com supports both hand-drawn mode (mouse or touchscreen) and font-generation mode, with transparent PNG export that drops directly into Word or PDF. Everything runs locally in your browser — no signature data is uploaded to any server.

Digital Signatures in Software Development

For developers, digital signatures extend well beyond contracts into core technical infrastructure:

Code signing: macOS and iOS require all apps to carry an Apple-issued digital signature; Windows requires kernel drivers to be signed by Microsoft. An expired or missing signature triggers security warnings or outright blocks execution.

HTTPS certificates: A website's SSL/TLS certificate is fundamentally a digital signature from a Certificate Authority (CA) on the site's public key — proving that key genuinely belongs to that domain.

JWT (JSON Web Token): The third segment is a digital signature generated with the server's private key, preventing tokens from being forged or tampered with.

Package integrity: npm, pip, Maven, and other package managers provide signing mechanisms that let you verify a downloaded package hasn't been altered by a man-in-the-middle.

Git commit signing: Signing commits with GPG lets anyone verify that a commit genuinely came from the claimed author, preventing commit forgery.

Choosing the Right Electronic Signature Approach