System and method for verifying the authenticity of executable images. The
system includes a validator that determines a reference digital signature
for an executable image using the contents of the executable image
excluding those portions of the executable that are fixed-up by a program
loader. The validator then subsequent to the loading of the executable
image determines an authenticity digital signature to verify that the
executable image has not been improperly modified. In addition, the
validator ensures that each of the pointers in the executable image have
not been improperly redirected.