I don’t understand what you mean by “keys” here. Nothing in encrypted. You generate codes by initiating the login process.
The way TOTP works is there is a key (usually in the form of a QR code) for TOTP apps. That key is stored in your TOTP app locally, but also often stored I’m the cloud of you use Google’s app. Codes are generated using that key and the current timestamp. Otherwise a valid code can’t be generated.
There is no encryption in SMS…
The messages aren’t encrypted at rest but, the connections are. You need a key in the physical sim card to intercept anything. You can’t just intercept and duplicate a sim card’s identifier like with 2G. No casual hacker is going to hack LTE or newer technologies, only professionals like governments and government backed spy agencies. Not saying it’s as secure as OT should be, but the effort and cost is not worth it most of the time.
And sim swap only works if you also have the person’s username and password for 2fa. For the issue mentioned in the article it does work because you dont need any knowledge or other factor other than the message itself to login. Single factor logins with not even needing to have a username, much less a password, are obviously going to be an issue, which is why I’m emphasizing, I’m interested in 2FA like a bank might use, not the issue mentioned in the article which is totally different.
I was talking about sms. All types of cryptographic code generation uses one or more keys. The sms type just uses one that only the sender holds, it’s never shared with anyone which can cause it to be more easily lost.
The sim cards and their cryptographic keys are just built into the phones, and the codes are swapped when you sign up, same concept as renovable sim cards.
And again, it doesn’t matter of a sms code is intercepted as much as the entire login method. If you dont have the username and password, what good does an sms code do for anything? The issue in the article is that there’s nothing else to know, just the current format of the set of codes being generated by the system. Then you can randomly guess a similar code and get access to a random person’s account. Much, much different from the use MFA which is worthless without ALL of the factors, not just a single one.
Exactly, so it does that job because it requires an entirely different and complex skill-set to intercept sms messages and you have to do both things now if sms 2FA is in place. With the issue in the article you dont even need to intercept sms meant for a particular user to get access to random users’ accounts, thus totally different issue.
I asked, what is better for a second factor than SMS?
It does, really poorly, for the reasons I’ve listed, and for the reasons in the OP.
With the issue in the article you dont even need to intercept sms meant for a particular user to get access to random users’ accounts, thus totally different issue.
Not a different issue at all. Exact same issue, with lower risk.
I asked, what is better for a second factor than SMS?
I answered this like 12 comments ago.
We’re going around in circles now so I’ll bid you good night.
The way TOTP works is there is a key (usually in the form of a QR code) for TOTP apps. That key is stored in your TOTP app locally, but also often stored I’m the cloud of you use Google’s app. Codes are generated using that key and the current timestamp. Otherwise a valid code can’t be generated.
The messages aren’t encrypted at rest but, the connections are. You need a key in the physical sim card to intercept anything. You can’t just intercept and duplicate a sim card’s identifier like with 2G. No casual hacker is going to hack LTE or newer technologies, only professionals like governments and government backed spy agencies. Not saying it’s as secure as OT should be, but the effort and cost is not worth it most of the time.
And sim swap only works if you also have the person’s username and password for 2fa. For the issue mentioned in the article it does work because you dont need any knowledge or other factor other than the message itself to login. Single factor logins with not even needing to have a username, much less a password, are obviously going to be an issue, which is why I’m emphasizing, I’m interested in 2FA like a bank might use, not the issue mentioned in the article which is totally different.
Okay I thought you were still talking about SMS.
No you do not. Most phones don’t even have this anymore.
Yes, and for the 3rd time, all the same vulnerabilities exist in MFA.
I was talking about sms. All types of cryptographic code generation uses one or more keys. The sms type just uses one that only the sender holds, it’s never shared with anyone which can cause it to be more easily lost.
The sim cards and their cryptographic keys are just built into the phones, and the codes are swapped when you sign up, same concept as renovable sim cards.
And again, it doesn’t matter of a sms code is intercepted as much as the entire login method. If you dont have the username and password, what good does an sms code do for anything? The issue in the article is that there’s nothing else to know, just the current format of the set of codes being generated by the system. Then you can randomly guess a similar code and get access to a random person’s account. Much, much different from the use MFA which is worthless without ALL of the factors, not just a single one.
The entire point of MFA is to protect against someone who does have your username and password…
Exactly, so it does that job because it requires an entirely different and complex skill-set to intercept sms messages and you have to do both things now if sms 2FA is in place. With the issue in the article you dont even need to intercept sms meant for a particular user to get access to random users’ accounts, thus totally different issue.
I asked, what is better for a second factor than SMS?
It does, really poorly, for the reasons I’ve listed, and for the reasons in the OP.
Not a different issue at all. Exact same issue, with lower risk.
I answered this like 12 comments ago.
We’re going around in circles now so I’ll bid you good night.