Final answer:
Encryption and traffic padding can be used to counter the traffic analysis attack.
Step-by-step explanation:
The security mechanism that can be used to counter the traffic analysis attack is Encryption. Encryption involves encoding the data in such a way that only authorized parties can access and understand it. By encrypting the traffic, it becomes difficult for an attacker to analyze and make sense of the transmitted data.
Another security mechanism that can be used is Traffic padding. Traffic padding involves adding extra data to the network packets to make them uniform in size. This makes it more challenging for an attacker to distinguish between different types of traffic.
While both options A and B help protect against traffic analysis attack, options C and D are not specifically designed to counter this type of attack. Timestamp is used to record the time of an event, and Digital signature is used to verify the authenticity and integrity of a message.