diff --git a/src/challenge-module.hpp b/src/challenge-module.hpp
index 603e2ff..1cc22ad 100644
--- a/src/challenge-module.hpp
+++ b/src/challenge-module.hpp
@@ -146,6 +146,9 @@
   static Name
   genDownloadName(const Name& caName, const std::string& requestId);
 
+  static std::string
+  generateSecretCode();
+
 public:
   const std::string CHALLENGE_TYPE;
   static const std::string WAIT_SELECTION;