In network security, what is “traffic analysis”?

Traffic analysis refers to the practice of intercepting and examining network messages to infer information without needing to decrypt the content of those messages. This technique allows an analyst to gather insights regarding patterns and behaviors in network traffic, such as the volume and frequency of messages, the timing of communications, and the identities of the parties involved, which can all potentially reveal sensitive information about the entities communicating or the nature of their interactions.

For instance, even if the data itself is encrypted and unreadable, the metadata—information such as the size of the messages or the timing of the exchanges—can still provide valuable intelligence. This aspect plays a critical role in threat identification and understanding the context of network activity, making traffic analysis an essential skill in cybersecurity.

Other options like encrypting messages or blocking suspicious traffic primarily focus on securing the network rather than analyzing it. Routing traffic through a VPN is a specific solution to enhance privacy and security and does not directly relate to the analysis of traffic patterns. Hence, the correct choice effectively captures the fundamental concept of traffic analysis in the realm of network security.