diff --git a/session/impl_redis.go b/session/impl_redis.go
index 759fdd0..3881492 100644
--- a/session/impl_redis.go
+++ b/session/impl_redis.go
@@ -42,16 +42,42 @@ func newProviderWithRedis(ctx context.Context, redisUrl string, ttl time.Duratio
 }
 
 func (p *provider_redis) New(input *Authorization) (string, error) {
-	sk := make_storagekey(input.Account)
-	_, err := p.redisClient.HSet(p.ctx, string(sk), input.ToStrings()).Result()
+	newsk := make_storagekey(input.Account)
+	prefix := input.Account.Hex()
+	sks, err := p.redisClient.Keys(p.ctx, prefix+"*").Result()
+	if err != nil {
+		logger.Println("session provider delete :", sks, err)
+		return "", err
+	}
+
+	for _, sk := range sks {
+		p.redisClient.HSet(p.ctx, sk, "inv", "true")
+		p.redisClient.Publish(p.ctx, p.deleteChannel, sk).Result()
+	}
+
+	for {
+		duplicated := false
+		for _, sk := range sks {
+			if sk == string(newsk) {
+				duplicated = true
+				break
+			}
+		}
+		if !duplicated {
+			break
+		}
+		newsk = make_storagekey(input.Account)
+	}
+
+	_, err = p.redisClient.HSet(p.ctx, string(newsk), input.ToStrings()).Result()
 	if err != nil {
 		return "", err
 	}
-	_, err = p.redisClient.Expire(p.ctx, string(sk), p.ttl).Result()
+	_, err = p.redisClient.Expire(p.ctx, string(newsk), p.ttl).Result()
 	if err != nil {
 		return "", err
 	}
-	pk := storagekey_to_publickey(sk)
+	pk := storagekey_to_publickey(newsk)
 	return string(pk), err
 }