diff --git a/BTP.markdown b/BTP.markdown
index e7e9f72..e08463b 100644
--- a/BTP.markdown
+++ b/BTP.markdown
@@ -68,7 +68,7 @@ If the sender starts sending a stream at time t according to the sender's clock,
 
 Each stream starts with a pseudo-random tag, which is TAG_LEN bytes long. The recipient calculates the tag in advance and uses it to recognise which sender the stream comes from and which incoming header key should be used.
 
-The tag for the i^th stream from the sender to the recipient in a given rotation period is the first TAG_LEN bytes of MAC(k, int(i)), where k is the sender's outgoing tag key. For simplicity we require that TAG_LEN <= MAC_LEN. Streams are counted starting from zero in each rotation period.
+The tag for the i^th stream from the sender to the recipient in a given rotation period is the first TAG_LEN bytes of MAC(k, int(i)), where k is the sender's outgoing tag key. For simplicity we require that TAG_LEN <<= MAC_LEN. Streams are counted starting from zero in each rotation period.
 
 > Implementation note: The current implementation uses TAG_LEN = 16.