diff --git a/exam/ex.tex b/exam/ex.tex
index c9f5802..36ec555 100644
--- a/exam/ex.tex
+++ b/exam/ex.tex
@@ -202,7 +202,9 @@
       also easily be able to obtain the factorization of the public key. If that
       was possible, the scheme would be broken.
 
-    \item \TODO
+    \item The strongest type of security the authors claim to achieve is
+      IND-CCA2. The authors use the Fujisaki-Okamoto transform to achieve
+      IND-CCA2 security.
 
     \item \TODO