The PIN needs to be at least 5 numbers long and must meet the following non-trivial attributes:
- The PIN cannot match the numeric representation of the first or last name of the user.
- The PIN cannot contain the primary extension or alternate extensions of the user.
- The PIN cannot contain the reverse of the primary extension or alternate extensions of the user.
- The PIN cannot contain groups of repeated digits, such as “408408” or “123123.”
- The PIN cannot contain only two different digits, such as “121212.”
- A digit cannot be used more than two times consecutively (for example, “28883”).
- The PIN cannot be an ascending or descending group of digits (for example, “012345” or “987654”).
- The PIN cannot contain a group of digits that are dialed in a diagonal, vertical or horizontal straight line on the phone keypad (for example, the user cannot use “159”, “159730”, “147”, “147365”, “123” or “123597” as a PIN