This essay presents “surreptitious communication design” (SCD), a framework for design in contentious political contexts. SCD is concerned with crafting messages that are meaningful for intended recipients, but illegible and/or inaccessible for adversaries who seek to undermine communications or harm participants. Borrowing concepts from cryptography and information theory, SCD's key theoretical concerns are described, as are several of the strategies and tactics through which it is operationalized. Two recent anti-human trafficking projects are compared, one developed from an SCD perspective, the other from a traditional mass communications approach. Finally, SCD is considered in relation to the burgeoning “Design for Good” movement.