Thanks once again I will try this.

Sorry I am new, but are online wallets safe for small amounts of BTC?

Yes, you may need to do this on both devices:

    Go to the main menu on the Google Authenticator app
    Click Settings
    Click Time correction for codes
    Click Sync now

What if your email account was hacked? SMS/phone call also isn't the most secure way to do it. Phone company can see those, greedy employee's or hackers who've hacked your phone company can get them.

In simple, the QR code method works like this. The website generates a big long random string of letters. They make it into a QR code so you don't have to type it in. You scan it, your phone saves the random letters.

When you open the app on your phone, your phone gets the current date and time and the random string and hashes it. Hashing it basically jumbles it up in a way that can't be easily reversed back, the end result is a six digit code.

You enter that in the website, and the website uses the same random string that they gave you before and the current date + time and does the same thing, hashes it. It should calculate the same six digit code. If the code you gave them matches the same one they calculated it'll let you in, if they don't it won't.

This way is MUCH more secure than SMS/email. You do not need internet access on your phone to do this, all your phone needs is the random letters and the right time (has to be almost to the second accurate or else you'll have a different code to the one the website generates). Someone wanting to hack your account needs the random letters and they are long and random, it'll take a LONG LONG time to guess them like a bitcoin private key. And if someone uses your phone and writes down the six digit code, it'll only be valid for 30 or so seconds.


Lucky Cris was wrong. This will work fine so long as both iPad and phone have the exact right time set. Try it out, I do something similar.

well, I feel better that you accepted my apology (yeah, that was my sorry ass version, lol), but at least you own an iTrash device... this coming from someone who owns many iDevices btw. If you worry about data your phone again... take a screenshot of your QR code (press home & power button together), then back that shit up to iCloud.

You know... my response had absolutely nothing to do with you or your question - that's my problem. I was where you are before, so I know better. So let's try this again....

Personally I prefer emailed, SMS, or phone call 2FA, but that's only because I'm not familiar with the QR code method. Okay I confess, I prefer to carry a clam shell phone, but I do have my iPad mini but still. If push comes to shove, one would think you'd be able to request that the exchange send the coins back to the originating address. In that situation, it's less likely that you're a person attempting to gain access to someone else's exchange account. It probably won't work, but a shot nonetheless.

When you enable 2FA they ask you to scan a QR code with your phone.

Before you scan it take a picture of the QR code and store it on something other than your phone, like a memory stick and keep it safe (if someone gets it they can login to your account without your phone).

If you lose your phone, you can use another phone to scan the QR code in the picture and you'll have 2FA for that account on that phone. Enter the code to login as normal. Additionally there is software you can download on your computer that can read it if you don't have a phone to do it with.

All jokes aside. I'm straight but would suck you off for 100btc

Looks to me that it's 2FA you know nothing about.

2FA Authentication is not related to Bitcoin, but a security setting of an online exchange: you can use bitcoin outside of exchanges (in desktop wallets or paper wallets) which do not require it.

If you lose your mobile, you would need to contact the exchange admins and in some way prove it's you. As long as you don't get a reply from them your money is stuck there. You need a private key to move the money, but usually exchanges don't give you your private key. They will only show the public key. Thus in this situation you need either to prove it's you, probably by sending a lot of personal information, or to find your phone again.

That's one of the major differences between using a desktop wallet and an online exchange.

I recommend that you take a photo of the QR code when setting up 2FA and keep it safe. If you lose your phone you can use it to get back into your account without having to deal with the website. Some websites don't have proper procedure in place to deal with lost 2FA devices. There is no "standard" way to do it, each website has it's own procedure to deal with it and it might be difficult to get back in.