By Chris Hoffman, HowToGeek.com, July 9, 2017
When you connect to a Wi-Fi network on your iPhone, you may see the words “Security Recommendation” appear beneath its name.
This is a warning that you’re connected to either an unsecured network or one encrypted with weak WEP security.
If you tap the name of the Wi-Fi network displaying “Security Recommendation” once you’re connected to it, you’ll see a more informative message.
In most cases, your iPhone will tell you that the current network is an “Unsecured Network”, also known as an open network. These networks don’t require any passphrase to connect and, therefore, don’t have any encryption.