The Security of E-signatures – A Digital Footprint That Does Not Lie

Summary:
This article explains how e-signatures remain secure, trustworthy and legally valid across Europe.

Key facts:

• E-signatures are legally equivalent to handwritten signatures across all EU countries (eIDAS).
• eIDAS 2.0 strengthens cross-border recognition and introduces the digital identity wallet.
• Every signed document includes an audit trail of IP addresses, timestamps and event logs.
• Visma Sign attaches a unique document identifier to enable later verification.
• Both strong and simple authentication methods are supported.
• Signed documents can be verified at any time via Visma Sign or Adobe Reader.

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E-signing is not only a modern way to approve documents. It is also one of the safest. For businesses in particular, electronic signing has become the preferred way to collect signatures quickly, securely and cost-effectively.

But how do you know that an electronically signed document is genuine? And what exactly ensures the legal validity, traceability and reliability of an e-signature?

This article explains the foundations of secure e-signing and what to look for when choosing a secure e-signature service such as Visma Sign.

Legislation is the foundation of e-signature security

Electronic signatures have been legally valid for decades. The European Union established the legal basis in 1999 when the first e-signature directive came into force. Today, the key regulation is the EU’s eIDAS Regulation, which has applied in all Member States since 2014 and was updated in 2024 as eIDAS 2.0.

According to Article 25 of the eIDAS Regulation, all EU Member States must accept electronic signatures as legally valid evidence in official documents — such as contracts, mandates or authorisations.

Equal recognition across Europe

A key benefit of eIDAS is harmonisation. A signature made electronically is legally valid not only in Finland but across the entire EU.

This unified legal framework has increased trust and reduced risk in cross-border business, enabling companies to conduct transactions more efficiently.

The power of traceability: The audit trail

E-signatures leave behind a complete digital trail, making them far more secure than handwritten signatures.
This audit trail provides indisputable evidence of:

• who signed
• when they signed
• the IP addresses used
• all time-stamped signature events

In Visma Sign, each signature is cryptographically bound to the document. Every page includes:

• the audit trail data
• a unique document identifier

This ensures the document can be verified at any time and that no changes have been made after signing.

Verifying the signer’s identity

A key part of a secure e-signature is confirming who the signer really is. In Visma Sign this happens through either strong authentication or simple authentication.

Strong authentication uses a reliable external source, typically bank credentials or a mobile certificate. When a document is signed in this way, the resulting PDF clearly shows the signer’s name, the time of signing and information about the authentication method.

Organisations may also choose simple authentication, in which the signature is drawn digitally for example if strong authentication is not available in a spesific country. Even then, Visma Sign records essential details such as the signer’s name, email address, IP address and timestamp. This keeps the document fully traceable, regardless of the authentication method used.

Verifying the signed document

Any electronically signed document can be verified. This involves checking who signed it, where and when it was signed, and ensuring that no changes have been made since. Verification proves both the authenticity and integrity of the document.

Visma Sign makes this straightforward. Each PDF contains a verification code that can be checked directly on the Visma Sign website, or the document can be validated using Adobe Reader’s built-in tools. This gives all parties confidence that the document is exactly as it was at the moment of signing.

If you want to learn more about the security of e-signing or how Visma Sign protects your agreements, our team is happy to help.

Terhi Tella is Senior Growth Marketing Specialist at Visma Sign. She’s inspired by content and communication that create real value, and always strives to see things from the customer’s perspective.