Quote from: masulum on October 30, 2020, 12:34:21 PM

about using open source 2FA, unfortunatelly, most of service currently using Google 2FA even no more updates for this service. How we can choose other 2FA if the site still using Google 2FA, maybe someone can give any explanation more about this, since lot of people says if Google 2FA not save etc, but exchange still prefer to use this service, how we (as user) can move to open source?

There is nothing special about Google 2FA. Any 2FA app should work.

Very simply, when you set up 2FA, the site displays for you a shared secret. This is usually in the form of a QR code, but sometimes it is a string of characters. Ideally sites will show you both - a QR code you can scan with your app and a string of characters you can write down as a back up. When you need to enter the 2FA code in the future, your app will combine that shared secret with the current time (floored to the nearest 30 seconds), hash it, and use part of the result to generate your 6 digit 2FA code. The website will do the same thing, and check that what you have entered matches what they have calculated.

The process for combining the secret with the time and hashing it is standardized, and all 2FA apps and websites do it the same way. (There is more info here if you are interested: https://en.wikipedia.org/wiki/Time-based_One-time_Password_algorithm). Given that, although the website says Google 2FA, any good open source 2FA app will work. See my post on the previous page of this thread for some good open source 2FA apps.