Many of the applied mathematics courses we teach touch upon a range of rich and important ethical issues -- issues that, for a number of reasons, are rarely openly discussed in class. In this work, we describe a sequence of activities co-designed and co-taught by philosophy and mathematics faculty in the hopes of bridging the divide between the application and implementation of modern cryptography and the ethical dilemmas it creates. Although we have specifically focused on one area of applied mathematics at one particular type of institution, we highlight throughout the work the areas in which our approach can be changed to suit different content areas and student populations.