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200-201 · Question #398

What is the impact of encryption on data visibility?

The correct answer is A. TLS 1.3 traffic cannot be decrypted and monitored. With the introduction of TLS 1.3, perfect forward secrecy (PFS) is mandatory, preventing passive decryption and monitoring of traffic by middleboxes, even if the private key is compromised.

Submitted by carter_n· Mar 6, 2026Security Monitoring

Question

What is the impact of encryption on data visibility?

Options

  • ATLS 1.3 traffic cannot be decrypted and monitored.
  • BTraffic decryption causes high CPU load on monitoring systems.
  • CTraffic decryption is needed for deep inspection of SSL traffic via NGFW.
  • DIPsec encryption of traffic is vulnerable to man-in-the-middle attacks.

How the community answered

(49 responses)
  • A
    88% (43)
  • B
    2% (1)
  • C
    8% (4)
  • D
    2% (1)

Why each option

With the introduction of TLS 1.3, perfect forward secrecy (PFS) is mandatory, preventing passive decryption and monitoring of traffic by middleboxes, even if the private key is compromised.

ATLS 1.3 traffic cannot be decrypted and monitored.Correct

TLS 1.3 mandates perfect forward secrecy (PFS) through the use of ephemeral keys, meaning that even if an attacker compromises the server's long-term private key, they cannot decrypt past recorded sessions or future sessions. This design prevents network middleboxes from passively decrypting and inspecting TLS 1.3 traffic, impacting deep packet inspection capabilities.

BTraffic decryption causes high CPU load on monitoring systems.

While traffic decryption can cause high CPU load, it's a consequence of the process, not the primary impact of encryption on data visibility in the context of advanced protocols like TLS 1.3 preventing inspection.

CTraffic decryption is needed for deep inspection of SSL traffic via NGFW.

This statement is true in general for older SSL/TLS versions where decryption is needed for deep inspection, but it does not accurately describe the impact of modern encryption (like TLS 1.3) which makes such decryption significantly harder or impossible for passive monitoring.

DIPsec encryption of traffic is vulnerable to man-in-the-middle attacks.

IPsec encryption, when properly implemented, is designed to prevent man-in-the-middle attacks by ensuring authenticity and integrity, not be vulnerable to them.

Concept tested: Impact of TLS 1.3 and Perfect Forward Secrecy on traffic monitoring

Source: https://learn.microsoft.com/en-us/windows/win32/security/tls/tls-1-3-overview

Topics

#TLS 1.3#Traffic decryption#Security monitoring challenges#Encryption impact

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