From 327d75c2d47febe97fb08822dbe33b3d3c209f28 Mon Sep 17 00:00:00 2001
From: Kei Hibino <ex8k.hibino@gmail.com>
Date: Wed, 6 Apr 2016 11:59:26 +0900
Subject: [PATCH] Add comments about irreducible binary polynomial.

---
 Crypto/MAC/CMAC.hs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Crypto/MAC/CMAC.hs b/Crypto/MAC/CMAC.hs
index 23ee66e..86bf464 100644
--- a/Crypto/MAC/CMAC.hs
+++ b/Crypto/MAC/CMAC.hs
@@ -96,6 +96,13 @@ bxor = B.xor
 cipherIPT :: BlockCipher k => k -> [Word8]
 cipherIPT = expandIPT . blockSize   where
 
+-- Data type which represents the smallest irreducibule binary polynomial
+-- against specified degree.
+--
+-- Maximum degree bit and degree 0 bit are omitted.
+-- For example, The value /Q 7 2 1/ corresponds to the degree /128/.
+-- It represents that the smallest irreducible binary polynomial of degree 128
+-- is x^128 + x^7 + x^2 + x^1 + 1.
 data IPolynomial
   = Q Int Int Int
 ---  | T Int