A method, apparatus and program storage device for program verification in an information handling system in which an application program runs on an operating system having a signature verification function for verifying a digital signature of the application program. Upon loading of the application program, the signature verification function of the operating system verifies the digital signature of the application program and, if the digital signature is verified, initiates execution of the application program. Upon initiation of execution of the application program, a verification testing function associated with the application program tests the signature verification function of the operating system by presenting to it a sequence of test digital signatures in a specified pattern of true and false signatures. If its test of the signature verification function of the operating system is successful, the application program initiates normal execution. Otherwise, the application program terminates without initiating normal execution.