1. Clients need secrets to talk with servers. Usually clients need to authenticate themselves. (Password).
2. In this case, the password is the OTP. Unlike a password, which is in *your head*, the OTP is a dynamic password sent to the phone via SMS. So if OTP is revealed?
2. In this case, the password is the OTP. Unlike a password, which is in *your head*, the OTP is a dynamic password sent to the phone via SMS. So if OTP is revealed?
3. Whoever gets the OTP, becomes you. This is not new type of attack, but one that we see on Banking all the time. So what does mAadhaar use OTP for?
4. It exchanges a secret with the Android App. And the secret is then used to generate VID, TOTP etc.
4. It exchanges a secret with the Android App. And the secret is then used to generate VID, TOTP etc.
5. So OTP gone->Secret gone->VID, TOTP->known to others.
6. In effect, your Aadhaar is taken over by whoever reads the OTP first. And is there a list of Apps that get Notifications first in Android? Is that order controllable? AFAIK, no. (Correct me if I am wrong on this)
6. In effect, your Aadhaar is taken over by whoever reads the OTP first. And is there a list of Apps that get Notifications first in Android? Is that order controllable? AFAIK, no. (Correct me if I am wrong on this)
7. And remember that this is a permanent take over. Unlike a bank account, you can't close it. And @UIDAI's customer support is well, 1947...
8. So what is the right way to do this initial setup? QR code scanning done offline, like WA, Google Authenticator, any decent 2FA.
8. So what is the right way to do this initial setup? QR code scanning done offline, like WA, Google Authenticator, any decent 2FA.
9. This way, you exchange secrets not by Send OTP->Get Secret, but Scan QR->Get Secret. A lot more safer. But UIDAI can only do three types of authentication (a) Biometric and (b) OTP. So they chose a really stupid thing, because of platform constraints.
10. When were they told about this? Oct 30, 2017. A full 8 months later, this architecture still stays as it is. That is platform limitations. Once baked in very hard to change. And all the makers are gone.
medium.com/karana/securit…
medium.com/karana/securit…
The answers on the first one by Baptiste, shows how common developers don't understand the vulnerabilities OTP authentication creates. In short, it is all context, and everyone doing it, does not mean, it is safe.
Remember phone gone, Aadhaar gone.
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Remember phone gone, Aadhaar gone.
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