In addition to the holy trinity of "somethings" discussed in this chapter (something you know, are, or have), it is also possible to base authentication on "something you do." For example, you might...

In addition to the holy trinity of "somethings" discussed in this chapter (something you know, are, or have), it is also possible to base authentication on "something you do." For example, you might need to press a button on your wireless access point to reset it, proving that you have physical access to the device.

a. Give another real-world example where authentication could be based on "something you do."

b. Give an example of two-factor authentication that includes "something you do" as one of the factors.