diff --git a/Efficient-Software-Implementations-of-ZUC.md b/Efficient-Software-Implementations-of-ZUC.md
index 6a87059..33eee73 100644
--- a/Efficient-Software-Implementations-of-ZUC.md
+++ b/Efficient-Software-Implementations-of-ZUC.md
@@ -58,6 +58,8 @@ $M=X_{aes}X^{-1}_{zuc}$
 
 $C=L\ 0x63+0x55$  
 
+只有这种S盒和AES盒构造完全同构的，用AESENCLAST时，使用0x63作为enc_key才有点意义。
+
 ```python
 from pyfinite import ffield
 from pyfinite import genericmatrix