Public Key Infrastructure (PKI) Practice Exam 2025 - Free PKI Practice Questions and Study Guide

The term 'digital signature' within the context of Public Key Infrastructure (PKI) refers specifically to a cryptographic mechanism that serves two main functions: authentication and integrity assurance of digital documents.

When a digital document is signed using a digital signature, a unique hash of the document is generated and then encrypted with the signer's private key. This process enables the recipient to verify who the document comes from (authentication) since only the holder of the private key could have created that signature. Additionally, if the document were altered in any way after being signed, the hash would no longer match upon verification, proving that integrity has been compromised. Thus, a digital signature provides strong assurance that the document has not been tampered with and confirms the identity of the signer, which is essential in many applications like contracts, financial transactions, and secure communications.

The other options do not accurately describe the function of a digital signature. For instance, verifying encryption types, encrypting passwords, or generating security alerts do not encompass the core purpose of a digital signature within a PKI framework, which focuses on authentication and integrity.