I finally set up 2FA on my Google account this weekend.
It struck me as incredibly odd that Google requires a phone number to enable 2FA. NIST recently advocated against using SMS for OoB auth. [0]
If I had been an account hijacker with the password (e.g. obtained via phishing) it would have been ludicrously simple for me to enable 2FA on someone else's account.
I don't understand, I already have an Android phone with Google Play Services installed. Why isn't pressing "Okay" on my phone sufficient? It's certainly not any more insecure than an SMS.
What I view as even worse is on the first attempt the SMS didn't go through, so I asked Google to give me a call. Evidently my provider blocks whatever number they're using to call out of, so my phone never rang. But Google left the verification code anyway, AS A VOICEMAIL!
My inner tin foil hat says Google wants a phone number for other purposes.
[0] www.securityweek.com/nist-denounces-sms-2fa-what-are-alternatives
Just like Twitter these days. "Telephone number is optional and for your security". 2 minutes later my new accounts are always locked and i need to provide a telephone number to enable it again. They used SMS until recently, now they use a call service which only works with a fraction of numbers. (Tried 2 thai, 1 cambodian number, none accepted)
I seriously dont get what they are trying to do other than creating a database of telephone numbers and locking users in third world countries out.
Also agree with that Google actually knows enough to just verifiy it based on my phone. Telephone number is not necessary, especially i "verified" my account in the past with a phone call, why again?
It seems to be the industry status quo now to assume that everyone uses a smartphone running either Android or IOS, and that everyone wants to use that device for authentication. Meanwhile the tech giants (especially those involved in advertising) probably like having that nice unique alphanumerical identifier for your profile — it tends to be the same for all services you use.
I really hope Fido U2F becomes a de facto alternative for 2FA.
But i agree on everything said
So now I just don't bother with trading cards at all.
Phones are ubiquitous enough that very few customers have to pay this cost.
Obviously, this reasoning doesn't (and shouldn't) extend to using phones for authentication.
Also services like Twitter that allow any rented SMS service and multiple accounts for each number this seems not be the reason why they ask for a number.
"I already have an Android phone with Google Play Services installed."
Guess what - Google already has your phone number before asking for it via the 2FA form. My guess is that the reason they have one platform-independent process for setting up 2FA is for iOS users.
Only if the phone number is the same one I use for my Android phone. But yes, I realize that any SIM I put into my phone will also be known by Google.
It's just an incredibly shit onboarding method. They already have a more secure way than SMS to determine the account owner, so why not offer it as an option?
It never seemed to be a security measure, but an anti-spam measure. You can buy captcha solving as a service for fractions of a cent, and bulk create thousands of accounts for sending spam. Buying working phone numbers is more hassle and more expensive, and will leave a payment trail if you use a service like Twilio.