<p>Some CS programs might offer basic or more advanced cryptography/security courses at the undergraduate level but these are usually during your junior/senior year. Also, some universities will also allow you to enroll in Graduate Classes during your senior year and you could always just ask the professor if you would be able to enroll in anyway.</p>
<p>In addition to CS classes, you should also be on the look out for Math courses, since crypto is usaully their domain.</p>