diff --git a/exam/ex.tex b/exam/ex.tex
index 8880809..a8fb389 100644
--- a/exam/ex.tex
+++ b/exam/ex.tex
@@ -36,7 +36,8 @@
   \item \textbf{(18 points)} 
   \begin{enumerate}
     \item 
-    \item \TODO
+    \item The type of symmetric cryptographic scheme introduced is a Message
+      Authentication Code (MAC).
     \item \TODO
     \item \TODO
     \item \TODO