Is it ensure, insure, or assure?
1650s, "pertaining to fingers," from Latin digitalis, from digitus (see digit). Meaning "using numerical digits" is from 1938, especially of computers after c.1945; in reference to recording or broadcasting, from 1960. Related: Digitize.
digital dig·i·tal (dĭj'ĭ-tl)
Of or resembling a finger or toe or an impression made by them.
Done or performed with a finger.