The use of 2FA (two-factor authentication) has been encouraged as it offers up a more secure way of logging into your accounts. However, even then, it is still not 100% secure as some methods that involve sending codes over SMS can also be hijacked, which is why security keys exist.
The problem with security keys is that you need to carry them with you, which can be a bit of a bother, but the good news for iPhone users is that you won’t have to anymore, at least if you are using a Google account. Google has recently updated its Smart Lock app for iOS devices where they now note that iPhone users can use their devices as a security key.
There are some caveats, and that is you can only use it with your Google accounts and that you will need to log into them through Chrome. You will also require Bluetooth enabled on both your phone and computer. This means that if you want to use a security key with other online accounts, you might be out of luck.
This isn’t exactly a new feature as previously, Google had allowed Android devices running on Android 7.0 and above to use their phones as a security key, so it looks like it is finally available for the iPhone.