How does a digital signature enhance cybersecurity?

A digital signature significantly enhances cybersecurity by providing proof of the signer's identity. This is achieved through cryptographic techniques that associate the signature with the contents of the document and the signer’s private key, confirming that the signer cannot deny having signed the document (non-repudiation).

When a digital signature is applied to a document, it creates a unique hash of the document's contents that is then encrypted using the signer's private key. When the document is later accessed, anyone can verify the signature using the corresponding public key. If the content has been altered, the hash will not match, indicating that the document has been tampered with. This mechanism not only asserts that the document has not been changed but also establishes the identity of the signer, which is crucial in preventing fraud and ensuring accountability in digital transactions.

The other options do not contribute to cybersecurity in the same way. Quick access to a document or formatting it for better readability does not address security concerns. Although signing a document before sharing may indicate approval, it lacks the identity verification aspect that ensures the authenticity of the signer, which is what makes digital signatures a strong tool for cybersecurity.