Ben uses a software-based token that changes its code every minute. What type of token is he using?

Ben is using a synchronous token, which is characterized by generating a new code at fixed time intervals, such as every minute. Synchronous tokens rely on a synchronized clock for both the token and the system it provides access to, ensuring that they produce the same code at the same time.

This time-based approach allows for an added layer of security, as the code is valid only for a short duration, typically matching the time it takes to enter the token. As a result, even if someone were to capture the code, it would quickly become obsolete, reducing the risk of unauthorized access.

In the context of the other options, static tokens do not change and provide the same code every time, while dynamic tokens change but are not necessarily time-based. Asynchronous tokens rely on a different method of verification rather than real-time synchronization, distinguishing them from synchronous tokens. The dynamic aspect might refer to tokens that can adapt based on certain conditions, but this does not specifically describe what Ben is using. Thus, the best characterization for the token he is utilizing is synchronous.