diff --git a/SM2性能优化（续）.md b/SM2性能优化（续）.md
index d4f97b3..adf4e68 100644
--- a/SM2性能优化（续）.md
+++ b/SM2性能优化（续）.md
@@ -21,7 +21,7 @@ prime order elliptic curves, §A.2](https://eprint.iacr.org/2015/1060)。这里
 * 使用NEON指令实现SELECT、MOVE操作，请参考https://github.com/emmansun/gmsm/discussions/134
 
 ## SM2签名、验签等算法优化
-* 改用NAT
+* 改用bigmod代替```big.Int```，请参考[sm2/enc: use bigmod and sm2ec instead of math/big and crypto/elliptic]()