Quote Originally Posted by worldofneil View Post
Very happy about this and already added it to my Fitbit watch (and my phone!)



(This is using the Auth app by Tejas Patel in the Fitbit app gallery)

Although I have to say the "window" to enter your password doesn't seem to be very big. So if you find you're getting told you've typed in an invalid code, check the time AND timezone on your device to make sure they're correct.

For like the last 6+ years I've been used to loading the app THEN loading the game, but now I'm finding that means the code it generated 20+ seconds earlier will have actually expired by the time I type it in due to the very short window. Not a problem though, just load the app when you're actually ready to type it in. I'm just mentioning this in case anyone else gets caught out by it!
While I cant speak for specifically how se does it. Software authenticator the codes are typically valid for 60 seconds.

Hardware authenticators such as security tokens a code will often work for upto 10 minutes.

The reason is basically due to time. Hardware authenticators will typically fall out of sync with the time as they age. This might only be 2 or 3 seconds a week but over a few years that can easily become several minutes. Software based ones. Pull the time from the device so they can be much more precise.