Aircrack-ng is a tool that can be used to crack keys used in WEP protocols in wireless networks.
Aircrack-ng is a complete suite of tools to assess WiFi network security. It focuses on different areas of WiFi security: Monitoring: Packet capture and export of data to text files for further processing by third party tools; Attacking: Replay attacks, deauthentication, fake access points and others via packet injection.
Official page: https://aircrack-ng.org/