(mod-expt 2 10 5) => 4
(mod-expt 2 10 500) => 24
(mod-expt signature 3 modulus) => 5972304273877744135569338397692020533504
(mod-expt 7 signing-exponent modulus) => 480035845964198162695390316681675930971456410079031402406756095511842878159233308075425733350601517651799075703860544976987140327389318592927018823188539796676610861096122316733992286199077843346650
In the last two tests, signature, modulus, and
signing-exponent have the same (large) values as those used in
the text and lecture.