(After the emergence of WLAN technology, "security" has become a shadow that always accompanies the word "wireless", and there are endless attacks and cracks on the security authentication encryption protocol involved in wireless network technology. Today, there may be hundreds or even thousands of articles on the Internet that describe how to attack and crack WEP, but how many people can actually successfully break the encryption algorithm of WEP? The author will introduce some of the encryption algorithms used in WEP. Common sense of encryption methods, and a method that even a rookie can successfully crack the WEP key by simply following the process. Of course, the ultimate purpose is still to allow reporters to make security settings to better prevent cracking. There are two articles in this series. In the first article, we first introduce the method of cracking WEP. In the second article, we introduce how to set WLAN security settings for better prevention.)