Interrogative subroutine
An interrogative subroutine was a subroutine that continuously asked the individual entering an access code to provide proof of identity. 

In 2371, while attempting to pose as Gul Dukat in order to shut down Terok Nor's counter-insurgency program, Garak noted that the gul had embedded several interrogative subroutines in his access code, something he attributed to the gul's paranoia. ()
Identification technology
Subroutines