CREST Practitioner Security Analyst (CPSA) Practice

What is the primary purpose of the Kerberos protocol?

1. A computer network authentication protocol that uses tickets

2. A method for securely transmitting files over a network

3. A protocol for managing network bandwidth

4. A way to encrypt sensitive information during transmission

The correct answer is: A computer network authentication protocol that uses tickets

The primary purpose of the Kerberos protocol is to facilitate secure authentication within a computer network. It achieves this by using tickets, which allow nodes to prove their identity over a non-secure network. Kerberos operates on the basis of a trusted third-party model, where a Key Distribution Center (KDC) authenticates users and services and subsequently issues tickets that can be used to access various services without repeatedly transmitting passwords across the network. This mechanism not only enhances security by preventing eavesdropping on password transmissions but also mitigates risks associated with replay attacks, as the tickets have a limited lifespan. In contrast, the other options don't accurately align with the primary function of Kerberos. The transmission of files is generally associated with protocols like FTP or SFTP, while network bandwidth management is typically handled by Quality of Service (QoS) protocols. Encryption for sensitive information during transmission refers more closely to protocols like SSL/TLS, which are specifically designed for secure communications rather than authentication.