Definition
Digital Signature
A high-security type of electronic signature built on cryptography, which proves who signed and confirms the document was not changed afterward.
In Depth
People often say "digital signature" when they just mean any online signature, but the term has a stricter technical meaning. When you sign, the document is processed with a private key that only you hold. Anyone can then use your public key to check two things at once: that the signature genuinely came from you, and that not a single character was altered since you signed. It gives authenticity, integrity, and non-repudiation, though it does not keep the contents secret.
The technical meaning is consistent across the US, UK and EU. One usage difference is worth knowing: in the US "digital signature" is often used loosely to mean any electronic signature, whereas in the UK and EU people tend to reserve it for the cryptographic version and use the eIDAS tier names for the legal categories.
Sources
- NIST Computer Security Resource Center Glossary - The result of a cryptographic transformation of data that, when properly implemented, provides source authentication, assurance of data integrity, and supports signatory non-repudiation.