Algorithm

The Twelfth Doctor likened Smartsuits to an algorithm. (TV: Oxygen)

The Seal of Rassilon badges used by the High Council of Gallifrey had an algorithm in their atomic structure. At the onset of the Siege of Trenzalore, the Eleventh Doctor affixed a seal to Handles, instructing the cyber-helmet to use the algorithm to decode the Question. (TV: The Time of the Doctor)