minor

Change-Id: I61b847985154a0199445062cee66b05cd4cf6143
diff --git a/src/detail/crypto-helpers.cpp b/src/detail/crypto-helpers.cpp
index 6956784..9decd97 100644
--- a/src/detail/crypto-helpers.cpp
+++ b/src/detail/crypto-helpers.cpp
@@ -342,8 +342,8 @@
   std::memcpy(&iv[8], reinterpret_cast<const uint8_t*>(&temp), 4);
   uint32_t increment = (payloadSize + 15) / 16;
   if (std::numeric_limits<uint32_t>::max() - counter < increment) {
-    // simply set counter to be 0. Will not hurt the property of being unique.
-    counter = 0;
+    NDN_THROW(std::runtime_error("Error incrementing the AES block counter:"
+                                 "too many blocks have been encrypted for the same request instance"));
   }
   else {
     counter += increment;