diff --git a/README b/README
index a1e31ab..df70f7b 100644
--- a/README
+++ b/README
@@ -21,3 +21,5 @@ Copyright (C) 2013 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
+
+The implementation is verified against the data in National Institute of Standards and Technology Special Publication 800-38A 2001 ED.