What is NOT a service provided by digital signatures?

Digital signatures play a critical role in ensuring the security and integrity of electronic communications and transactions. The services provided by digital signatures include integrity, authentication, and non-repudiation.

Integrity ensures that the message has not been altered in any way during transmission. When a digital signature is applied to a document, it creates a unique hash of the document’s content. If even a single bit of the document changes, the hash will change, indicating that the document's integrity has been compromised.

Authentication is achieved through digital signatures as they confirm the identity of the signer. By using a private key to sign a document, the signer can be verified with the corresponding public key, establishing that the message truly comes from them.

Non-repudiation prevents the signer from denying the authenticity of their signature on the document. Because a digital signature is generated using the signer’s private key, it provides a definitive proof of the signer’s consent, ensuring that they cannot later claim that they did not sign the document.

While all the other options are fundamental services associated with digital signatures, authorization is not directly a service provided by digital signatures. Authorization typically refers to the permissions or rights granted to users within a system, which goes beyond what digital signatures can offer.