CompTIA CASP+ Practice Test

What security feature is designed to ensure that a breach of one session does not compromise future sessions?

1. Session timeout

2. Perfect Forward Secrecy

3. Digital signatures

4. Multifactor authentication

The correct answer is: Perfect Forward Secrecy

The correct answer is focused on the concept of Perfect Forward Secrecy (PFS), which is a security feature used primarily in cryptographic protocols, such as TLS (Transport Layer Security), to enhance the security of session keys. PFS ensures that even if a session key is compromised, the keys for future sessions remain secure and cannot be derived from the compromised information. PFS achieves this by generating unique session keys for each session using ephemeral key exchanges. This means that a new pair of keys is created for each session and these keys are not reused. As a result, any breach that affects one session does not impact the security of subsequent sessions because each one operates independently from previous ones. Other options do not provide the same level of protection or are not directly aimed at preventing the compromise of future sessions. For instance, session timeouts can mitigate risks by ending sessions after a period of inactivity, but they do not prevent the potential for session keys to be compromised. Digital signatures ensure the integrity and authenticity of messages but do not inherently protect subsequent sessions. Multifactor authentication enhances access security but is focused on verifying identity rather than securing session keys for future interactions.