Prior to 2004, the encryption types available were WEP and WPA.
Wired Equivalent Privacy (WEP) – This was the first-ever security protocol, used from 1999 to 2004, which makes it the oldest type. Though WEP was designed to protect networks, it had poor security and was difficult to configure. A WiFi network using WEP today is considered the least secure and should be upgraded or replaced in order to protect your internet activity.
WiFi Protected Access (WPA) – As an improvement on WEP, WPA was created in 2003, and offers more secure encryption for your WiFi network, but still isn’t considered the best security option. Why? Some elements of WEP were kept as part of WPA to allow for compatibility with older devices. This means WPA has similar vulnerabilities to WEP and can be hacked more easily than its successor, WPA2.