diff -r 39fa24c5d85e -r ff053e2766e8 hws/hw07.tex
--- a/hws/hw07.tex	Thu Nov 12 08:25:22 2015 +0000
+++ b/hws/hw07.tex	Thu Nov 12 22:53:44 2015 +0000
@@ -17,6 +17,10 @@
       still encrypt this message and your grandmother take the
       effort to decrypt it? 
 
+      (Hint: The answer has nothing to do with preserving the
+      privacy of your grandmother and nothing to do with keeping
+      her birthday wishes supersecret.)
+
 \item One part of achieving privacy (but not the only one) is
       to properly encrypt your conversations on the Internet.
       But this is fiercely resisted by some spy agencies.