Abstract: Rather than employing simple static personal identification numbers (PINs) that are susceptible to hacking, the disclosed security system provides multiple levels of security that may be selected by a user, based on his or her particular level of sensitivity at any given time or with respect to any given data. One level employs an algorithm that changes values, where the algorithm is known by the user. For example, the algorithm may be a series of digits based on the following: hour of day, day of week, quarter of the year, a.m. or p.m., day of the month, and month of the year. If the user knows the order of such, the user can readily generate the appropriate numeric code corresponding to the current time, and since the time continually changes, the code necessarily changes likewise. Another level sends a random part to a user, such as over their pager or phone, which they append to some user-defined, fixed portion of their PIN, or used in addition to their PIN.