在RFID系统运用中，标签与读写器之间进行双向认证的时候，会涉及共享密钥。现有的认证过程中用到 的共享密钥大多是事先设定好的，但该方式存在一定的安全缺陷。针对读写器为一组标签生成一个共同的密钥运用场景，提 出了一种动态方式通过无线方法生成共享密钥的算法，从而解决事先设置好密钥而存在的安全缺陷问题。

In the application of RFID system, the mutual authentication between the tag and the reader involves the shared key. Most of the shared keys used in the authentication process are set in advance, but there are some security flaws. Aiming at the application scene that the reader generates a common key for a set of tags, this paper puts forward a shared key generation algorithm in dynamic and wireless way, to solve the problem of pre-setting the key.