diff --git a/sm2/sm2_keyexchange.go b/sm2/sm2_keyexchange.go
index 1e9f815..f606bc4 100644
--- a/sm2/sm2_keyexchange.go
+++ b/sm2/sm2_keyexchange.go
@@ -53,8 +53,6 @@ func (ke *KeyExchange) Destroy() {
 	destroyBytes(ke.z)
 	destroyBytes(ke.peerZ)
 	destroyBigInt(ke.r)
-	destroyPublicKey(ke.secret)
-	destroyPublicKey(ke.peerSecret)
 	destroyPublicKey(ke.v)
 }
 
diff --git a/sm2/sm2ec/sm2ec.go b/sm2/sm2ec/sm2ec.go
index 560d41e..da99f9e 100644
--- a/sm2/sm2ec/sm2ec.go
+++ b/sm2/sm2ec/sm2ec.go
@@ -8,7 +8,6 @@ import (
 	_sm2ec "github.com/emmansun/gmsm/internal/sm2ec"
 )
 
-// TODO: will merge it with sm2p256_generic.go from golang 1.18 with generic support.
 type sm2Curve struct {
 	newPoint func() *_sm2ec.SM2P256Point
 	params   *elliptic.CurveParams
diff --git a/sm9/sm9.go b/sm9/sm9.go
index 9005164..ccba988 100644
--- a/sm9/sm9.go
+++ b/sm9/sm9.go
@@ -487,12 +487,6 @@ func (ke *KeyExchange) Destroy() {
 	if ke.r != nil {
 		ke.r.SetInt64(0)
 	}
-	if ke.secret != nil {
-		ke.secret.Set(bn256.Gen1)
-	}
-	if ke.peerSecret != nil {
-		ke.peerSecret.Set(bn256.Gen1)
-	}
 	if ke.g1 != nil {
 		ke.g1.SetOne()
 	}