All features encoded in a particular key always have the same licensed duration, so activation keys can be classified as permanent or time-based. You can request and apply another key with a different set of features to the same Cisco ASA device at any future point in time. After Cisco generates a key for a given device, you cannot separate individual features from this licensed package. The complete set of activation keys resides in a hidden partition of the built-in flash device of a Cisco ASA other nonvolatile internal memory structures maintain a backup copy of that information. Each activation key is only valid for the particular hardware platform with the specific encoded serial number. A series of five hexadecimal numbers, as shown at the top of the output in Example 3-1, typically represents that string. An activation key is an encoded bit string that defines the list of features to enable, how long the key would stay valid upon activation, and the specific serial number of a Cisco ASA device.

What is an activation key