6 ms·

SMS is not the only – or preferred – 2FA mechanism for Google accounts. You can use any TOTP authenticator application, Google mobile applications like Gmail, p

SMS is not the only – or preferred – 2FA mechanism for Google accounts. You can use any TOTP authenticator application, Google mobile applications like Gmail, physical security keys, or backup codes. Having a single phone number is not a problem for dealing with multiple 2FA-enabled Google accounts.

hansvm 6y ago
> or preferred I just made a new Google account a couple hours ago, and it definitely looks like the preferred mechanism. - There's one stage in the signup flow you can't bypass without SMS (granted, it doesn't automatically save that number to the account if you opt out, so that's nice). - When setting up 2FA you're given giant messaging encouraging you to use a phone number. There's tiny text for other 2FA options. - Those other 2FA options don't actually include TOTP. To enable TOTP you have to enable a "primary" 2FA solution (SMS, hardware key, or push notification), then enable a "secondary" 2FA solution (which can include TOTP), and if you're concerned about the shitty security SMS provides you then need to remove that as a 2FA option. Edit: Mind you, it's probably reasonable given the state of the rest of their ecosystem to not have TOTP as the 2FA for your Google account (like if you have a chicken and egg problem trying to get into an android device with a TOTP app), but TOTP doesn't seem to be anywhere near as preferred as SMS. That, and they do support hardware tokens out of the box (even if the UI doesn't make that super clear), so that's a step in the right direction.
- skynet-9000 6y ago
  Even though TOTP is provably safer than SMS, it looks like the reason why they want SMS/push as a "primary" is so that they can suck in more phone numbers, since hardware keys have an additional cost that most people won't have. Phone numbers will let them do better ad targeting.
  - amk10 6y ago
    That is Silicon Valley's reason for 2FA in a nutshell. Phone numbers can only be obtained with identification in many countries. It is a privacy nightmare.
  - minhazm 6y ago
    It may be safer but it is way less user friendly. If you lose your phone with Google Authenticator (or any competitor), you will lose access to your accounts. You'll need to find your backup codes or go through the process to reset your accounts, which can be very cumbersome. Once someone has to go through this process they won't want to use 2FA anymore, I've seen it happen to many people. But if you break or lose your cell phone you can just get a new one, and you have access to your 2FA token again immediately. It's much easier for people to work with. Yes it's less secure technically, but that sacrifice is worth it for a lot of people.
    - 1cvmask 6y ago
      There are authenticators out there that can run on multiple devices and have multiple backup and restore options (with SIM Swap prevention) like saas pass.
    - jasonjayr 6y ago
      You can backup your 2FA TOTP qrcodes to physical cold storage, and you can keep backups. Most non-technical people understand the process of "keep this print out safe + secure" However you can lose control of your SMS phone number any number of ways that are beyond your control. It's frustrating that so many providers push SMS as the only 2FA, when there are so many problems with it, and TOTP is provably better, privacy preserving, and much easier to work with.
      - foxrider 6y ago
        I don't know if you ever worked with tech-illiterate people, but there is no way that they would print out or write down a list of codes or keep something in cold storage. Hell, even if they know how to. It's too much effort for something like email, and yet they wouldn't realize the importance until it's too late. I personally had to deal with an aging woman who had her online banking password set to her name followed by the year she was born in, and was unwilling to use the USB security key that the bank started providing. There was more than a million in her account. She couldn't be fucked to secure that kind of money with a free-of-charge easy to use key. It was not a case of an elderly woman struggling to remember her password or not understanding how to use it. In her mind she deserved the access to her account just on the merit of it being "hers", and she saw the security as an unnecessary ritual that the bank used as a barrier between her and her money and nothing could convince her otherwise.
  - tialaramex 6y ago
    > Even though TOTP is provably safer than SMS This seems like it would depend heavily on your threat model, especially keeping in mind that we're talking about second factors here. For example, one threat is that bad guys gain access to the authentication data of the Relying Party. For example, maybe they find the daily backups are in backups.tgz on the web server for convenient downloading. Or maybe you never changed the password on the MySQL server. This is of course one way bad guys might have everybody's passwords, the first factor... For TOTP the stored credentials include a "seed" value used to generate those six digit codes, and so by the relying party to confirm your code is correct. So for that credential access threat, the bad guys also have your TOTP codes and you're no better off with TOTP. Whereas for SMS the stored credentials just include a phone number to send the one use codes to, bad guys having that isn't great news necessarily, but it doesn't actually give them the codes. Even if the one-use codes are stored in the same place as permanent credentials (which they may not be) and thus accessible to bad guys, the bad guys can't necessarily arrange to see them before you use them, and in any case can't arrange for you not to wonder why you're getting all these one-use SMS codes suddenly. In contrast notably Security Keys don't end up with the Relying Party having any secrets at all, and so bad guys do not learn how to impersonate your users even if they somehow have access to the same means you use to authenticate those users.
    - skynet-9000 6y ago
      Read more about HOTP and TOTP here: https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password Implementations vary, but TOTP was developed on top of HOTP and presents a standardized method to expire OTP codes.
- deleted 6y ago
  [deleted]
- weird-eye-issue 6y ago
  It's because people lose access to their phone number rarely. It would be pretty much expected for somebody to not realize their Google Authenticator codes aren't backed up before losing/selling their phone or losing their Yubikey before backing up the private key off it. As somebody who doesn't use SMS 2FA, I still think it's a great middle ground for the average user.
  - loloquwowndueo 6y ago
    Untrue. Particularly in emerging economies where prepaid is much more common, it’s quite normal for people whose phone becomes unavailable to just buy a new one with an entirely new number and just tell everyone their number has changed.
    - gruez 6y ago
      emerging economies don't have number porting?
      - loloquwowndueo 6y ago
        They do, but a lot of people don’t bother and just get a new number along with the new phone.
      - deleted 6y ago
        [deleted]
    - deleted 6y ago
      [deleted]
    - weird-eye-issue 6y ago
      Then they wouldn't use their temporary number for 2FA. But for a lot of people they have their number for decades and are not going to suddenly lose it as easily as you can drop your phone into the ocean.
  - pilsetnieks 6y ago
    They finally updated Google Authenticator to enable backups and transfers between devices in December last year.[1] Also, there are other 2FA apps like Authy that are more user friendly and have been transferrable for years now. However, I think you do have a point. The attacks that rely on intercepting SMS messages are cumbersome and are really feasible only for high value targets. [1] https://www.androidpolice.com/2020/05/07/google-authenticator-gets-its-first-update-in-years-finally-lets-you-transfer-accounts-between-devices-apk-download/ https://www.androidpolice.com/2020/05/07/google-authenticato...
- alsetmusic 6y ago
  > There's one stage in the signup flow you can't bypass without SMS Which impedes the ability to sign up if one does not own a smartphone. I’m sure many people who are unhoused and rely on dumb phones need access to email to apply for jobs. Granted, I’m selecting a niche of a niche, but it’s a prime example of how badly the system is stacked against people trying to claw their way out of poverty.
  - jimktrains2 6y ago
    Feature phones are perfectly capable of sms.
    - hansvm 6y ago
      I didn't test this very much with the current Google flow. I know FB and whatnot require a post-paid cell plan (i.e., with your name attached) at that portion of their sign-up flow, and that precludes a lot of the cheaper phone options.
      - jimktrains2 6y ago
        1) Type of plan as no baring on feature vs smart phone. 2) Maybe pre-paid plans are contract based.
- bobsmooth 6y ago
  > There's one stage in the signup flow you can't bypass without SMS You used to be able to make gmail accounts without a phone by using an Android TV device. I wonder if that still works.
dathinab 6y ago
Except that you might need to first setup phone/sms 2FA to then be able to setup any other 2FA auth, without being able to fully disable phone/sms based 2FA auth. I'm not sure if it's still that way, but when I setup 2FA I could not directly setup non phone/sms 2FA (e.g. Yubikey, non google authenticator apps). Worse even through I then explicitly disabled phone/sms based 2FA google at some point just switched it back one. Worse there had been multiple times where having the 2nd factor but not the first (password) was enough to combine it with social engineering to completely take over an account. Some security researcher go hacked by this. Again I'm not sure it's still that way, but I don't trust Google anymore to not accidentally but a 2FA related vulnerability which makes the account less secure into their authentication flow. They either don't care (likely) or don't have the competency to handle this (unlikely). Well it's one of the reasons I'm slowly moving away from Google.
simion314 6y ago
>a single phone number is not a problem for dealing with multiple 2FA-enabled Google accounts. It increases the risk that a ban on an account will bring all of them down since you link them with same phone number identity.
csdreamer7 6y ago
Google makes using a different TOTP authenticator very difficult. First, I need to register a phone number as 2FA. Only then can I choose an alternate method, get codes, and have to select Google Authenticator to use my Open Source authenticator, Aegis. Does not say Google Auth or any TOTP; specifically only says Google Auth. I was worried Aegis would not work until I tried it. Why not show choices on the sign up screen? Why do I need to register a phone number first? It is very insecure in the USA. Data collection? Hold out from when a phone number was the only real 2FA and a TOTP was under additional options? If the latter, that needs to change if 2FA is going to be mandatory.
- tadfisher 6y ago
  This is doubly silly because the Google Authenticator team created the otpauth:// URI scheme which every authenticator application supports. I integrated it in pass-otp, for example.
- foobar33333 6y ago
  >Why do I need to register a phone number first? It's an anti spam/anti abuse feature. Getting access to new phone numbers that aren't recognized as virtual is pretty hard.

hansvm 6y ago

> or preferred I just made a new Google account a couple hours ago, and it definitely looks like the preferred mechanism. - There's one stage in the signup flow you can't bypass without SMS (granted, it doesn't automatically save that number to the account if you opt out, so that's nice). - When setting up 2FA you're given giant messaging encouraging you to use a phone number. There's tiny text for other 2FA options. - Those other 2FA options don't actually include TOTP. To enable TOTP you have to enable a "primary" 2FA solution (SMS, hardware key, or push notification), then enable a "secondary" 2FA solution (which can include TOTP), and if you're concerned about the shitty security SMS provides you then need to remove that as a 2FA option. Edit: Mind you, it's probably reasonable given the state of the rest of their ecosystem to not have TOTP as the 2FA for your Google account (like if you have a chicken and egg problem trying to get into an android device with a TOTP app), but TOTP doesn't seem to be anywhere near as preferred as SMS. That, and they do support hardware tokens out of the box (even if the UI doesn't make that super clear), so that's a step in the right direction.

skynet-9000 6y ago
Even though TOTP is provably safer than SMS, it looks like the reason why they want SMS/push as a "primary" is so that they can suck in more phone numbers, since hardware keys have an additional cost that most people won't have. Phone numbers will let them do better ad targeting.
- amk10 6y ago
  That is Silicon Valley's reason for 2FA in a nutshell. Phone numbers can only be obtained with identification in many countries. It is a privacy nightmare.
- minhazm 6y ago
  It may be safer but it is way less user friendly. If you lose your phone with Google Authenticator (or any competitor), you will lose access to your accounts. You'll need to find your backup codes or go through the process to reset your accounts, which can be very cumbersome. Once someone has to go through this process they won't want to use 2FA anymore, I've seen it happen to many people. But if you break or lose your cell phone you can just get a new one, and you have access to your 2FA token again immediately. It's much easier for people to work with. Yes it's less secure technically, but that sacrifice is worth it for a lot of people.
  - 1cvmask 6y ago
    There are authenticators out there that can run on multiple devices and have multiple backup and restore options (with SIM Swap prevention) like saas pass.
  - jasonjayr 6y ago
    You can backup your 2FA TOTP qrcodes to physical cold storage, and you can keep backups. Most non-technical people understand the process of "keep this print out safe + secure" However you can lose control of your SMS phone number any number of ways that are beyond your control. It's frustrating that so many providers push SMS as the only 2FA, when there are so many problems with it, and TOTP is provably better, privacy preserving, and much easier to work with.
    - foxrider 6y ago
      I don't know if you ever worked with tech-illiterate people, but there is no way that they would print out or write down a list of codes or keep something in cold storage. Hell, even if they know how to. It's too much effort for something like email, and yet they wouldn't realize the importance until it's too late. I personally had to deal with an aging woman who had her online banking password set to her name followed by the year she was born in, and was unwilling to use the USB security key that the bank started providing. There was more than a million in her account. She couldn't be fucked to secure that kind of money with a free-of-charge easy to use key. It was not a case of an elderly woman struggling to remember her password or not understanding how to use it. In her mind she deserved the access to her account just on the merit of it being "hers", and she saw the security as an unnecessary ritual that the bank used as a barrier between her and her money and nothing could convince her otherwise.
- tialaramex 6y ago
  > Even though TOTP is provably safer than SMS This seems like it would depend heavily on your threat model, especially keeping in mind that we're talking about second factors here. For example, one threat is that bad guys gain access to the authentication data of the Relying Party. For example, maybe they find the daily backups are in backups.tgz on the web server for convenient downloading. Or maybe you never changed the password on the MySQL server. This is of course one way bad guys might have everybody's passwords, the first factor... For TOTP the stored credentials include a "seed" value used to generate those six digit codes, and so by the relying party to confirm your code is correct. So for that credential access threat, the bad guys also have your TOTP codes and you're no better off with TOTP. Whereas for SMS the stored credentials just include a phone number to send the one use codes to, bad guys having that isn't great news necessarily, but it doesn't actually give them the codes. Even if the one-use codes are stored in the same place as permanent credentials (which they may not be) and thus accessible to bad guys, the bad guys can't necessarily arrange to see them before you use them, and in any case can't arrange for you not to wonder why you're getting all these one-use SMS codes suddenly. In contrast notably Security Keys don't end up with the Relying Party having any secrets at all, and so bad guys do not learn how to impersonate your users even if they somehow have access to the same means you use to authenticate those users.
  - skynet-9000 6y ago
    Read more about HOTP and TOTP here: https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password Implementations vary, but TOTP was developed on top of HOTP and presents a standardized method to expire OTP codes.
deleted 6y ago
[deleted]
weird-eye-issue 6y ago
It's because people lose access to their phone number rarely. It would be pretty much expected for somebody to not realize their Google Authenticator codes aren't backed up before losing/selling their phone or losing their Yubikey before backing up the private key off it. As somebody who doesn't use SMS 2FA, I still think it's a great middle ground for the average user.
- loloquwowndueo 6y ago
  Untrue. Particularly in emerging economies where prepaid is much more common, it’s quite normal for people whose phone becomes unavailable to just buy a new one with an entirely new number and just tell everyone their number has changed.
  - gruez 6y ago
    emerging economies don't have number porting?
    - loloquwowndueo 6y ago
      They do, but a lot of people don’t bother and just get a new number along with the new phone.
    - deleted 6y ago
      [deleted]
  - deleted 6y ago
    [deleted]
  - weird-eye-issue 6y ago
    Then they wouldn't use their temporary number for 2FA. But for a lot of people they have their number for decades and are not going to suddenly lose it as easily as you can drop your phone into the ocean.
- pilsetnieks 6y ago
  They finally updated Google Authenticator to enable backups and transfers between devices in December last year.[1] Also, there are other 2FA apps like Authy that are more user friendly and have been transferrable for years now. However, I think you do have a point. The attacks that rely on intercepting SMS messages are cumbersome and are really feasible only for high value targets. [1] https://www.androidpolice.com/2020/05/07/google-authenticator-gets-its-first-update-in-years-finally-lets-you-transfer-accounts-between-devices-apk-download/ https://www.androidpolice.com/2020/05/07/google-authenticato...
alsetmusic 6y ago
> There's one stage in the signup flow you can't bypass without SMS Which impedes the ability to sign up if one does not own a smartphone. I’m sure many people who are unhoused and rely on dumb phones need access to email to apply for jobs. Granted, I’m selecting a niche of a niche, but it’s a prime example of how badly the system is stacked against people trying to claw their way out of poverty.
- jimktrains2 6y ago
  Feature phones are perfectly capable of sms.
  - hansvm 6y ago
    I didn't test this very much with the current Google flow. I know FB and whatnot require a post-paid cell plan (i.e., with your name attached) at that portion of their sign-up flow, and that precludes a lot of the cheaper phone options.
    - jimktrains2 6y ago
      1) Type of plan as no baring on feature vs smart phone. 2) Maybe pre-paid plans are contract based.
bobsmooth 6y ago
> There's one stage in the signup flow you can't bypass without SMS You used to be able to make gmail accounts without a phone by using an Android TV device. I wonder if that still works.

dathinab 6y ago

Except that you might need to first setup phone/sms 2FA to then be able to setup any other 2FA auth, without being able to fully disable phone/sms based 2FA auth. I'm not sure if it's still that way, but when I setup 2FA I could not directly setup non phone/sms 2FA (e.g. Yubikey, non google authenticator apps). Worse even through I then explicitly disabled phone/sms based 2FA google at some point just switched it back one. Worse there had been multiple times where having the 2nd factor but not the first (password) was enough to combine it with social engineering to completely take over an account. Some security researcher go hacked by this. Again I'm not sure it's still that way, but I don't trust Google anymore to not accidentally but a 2FA related vulnerability which makes the account less secure into their authentication flow. They either don't care (likely) or don't have the competency to handle this (unlikely). Well it's one of the reasons I'm slowly moving away from Google.

simion314 6y ago

>a single phone number is not a problem for dealing with multiple 2FA-enabled Google accounts. It increases the risk that a ban on an account will bring all of them down since you link them with same phone number identity.

csdreamer7 6y ago

Google makes using a different TOTP authenticator very difficult. First, I need to register a phone number as 2FA. Only then can I choose an alternate method, get codes, and have to select Google Authenticator to use my Open Source authenticator, Aegis. Does not say Google Auth or any TOTP; specifically only says Google Auth. I was worried Aegis would not work until I tried it. Why not show choices on the sign up screen? Why do I need to register a phone number first? It is very insecure in the USA. Data collection? Hold out from when a phone number was the only real 2FA and a TOTP was under additional options? If the latter, that needs to change if 2FA is going to be mandatory.

tadfisher 6y ago
This is doubly silly because the Google Authenticator team created the otpauth:// URI scheme which every authenticator application supports. I integrated it in pass-otp, for example.
foobar33333 6y ago
>Why do I need to register a phone number first? It's an anti spam/anti abuse feature. Getting access to new phone numbers that aren't recognized as virtual is pretty hard.