diff --git a/lib/api_common.js b/lib/api_common.js
index 34c92f7..60156d8 100644
--- a/lib/api_common.js
+++ b/lib/api_common.js
@@ -216,7 +216,7 @@ class API {
       err.code = 40001;
       throw err;
     }
-    return this.getAccessToken();
+    throw new Error('can\'t set access token');
   }
 }
 
diff --git a/lib/util.js b/lib/util.js
index 1f9341f..2efd3ae 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -1,4 +1,5 @@
 'use strict';
+const crypto = require('crypto');
 
 /*!
  * 对提交参数一层封装，当POST JSON，并且结果也为JSON时使用 */
@@ -42,3 +43,30 @@ function _replaceOneChar(c) {
 exports.replaceJSONCtlChars = function (str) {
   return str.replace(JSONCtlCharsRE, _replaceOneChar);
 };
+
+/**
+ * 小程序加密数据解密算法
+ * https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/signature.html
+ * @param {string} sessionKey
+ * @param {string} iv
+ * @param {string} encryptedData
+ * @returns {Object}
+ */
+exports.decryptDataForMiniProgram = function (sessionKey, iv, encryptedData) {
+  const sessionKeyBuffer = Buffer.from(sessionKey, 'base64');
+  const ivBuffer = Buffer.from(iv, 'base64');
+  const encryptedBuffer = Buffer.from(encryptedData, 'base64');
+
+  try {
+    const decipher = crypto.createDecipheriv('aes-128-cbc', sessionKeyBuffer, ivBuffer);
+    // 设置自动 padding 为 true，删除填充补位
+    decipher.setAutoPadding(true);
+    const decoded =
+        decipher.update(encryptedBuffer, 'binary', 'utf8') +
+        decipher.final('utf8');
+
+    return JSON.parse(decoded);
+  } catch (err) {
+    throw new Error('解密失败');
+  }
+};
diff --git a/package.json b/package.json
index 12d800f..29fa0f0 100644
--- a/package.json
+++ b/package.json
@@ -1,5 +1,5 @@
 {
-  "name": "co-wechat-api",
+  "name": "co-wechat-api-new",
   "version": "3.11.0",
   "description": "微信公共平台Node库API，ES6版本",
   "main": "index.js",
@@ -30,7 +30,7 @@
     "rewire": "*",
     "travis-cov": "*"
   },
-  "author": "Jackson Tian",
+  "author": "Salamander",
   "license": "MIT",
   "readmeFilename": "README.md",
   "directories": {