如何在flutter项目中存储AES私钥？

import 'package:shared_preferences/shared_preferences.dart';

// 存储AES私钥
void saveAESPrivateKey(String privateKey) async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  prefs.setString('aes_private_key', privateKey);
}

// 读取AES私钥
Future<String> getAESPrivateKey() async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  return prefs.getString('aes_private_key');
}

import 'package:flutter_secure_storage/flutter_secure_storage.dart';

// 存储AES私钥
void saveAESPrivateKey(String privateKey) async {
  final storage = new FlutterSecureStorage();
  await storage.write(key: 'aes_private_key', value: privateKey);
}

// 读取AES私钥
Future<String> getAESPrivateKey() async {
  final storage = new FlutterSecureStorage();
  return await storage.read(key: 'aes_private_key');
}