Wow, this is simultaneously really cool from a usability perspective, but terrifying from a security perspective. A non changing PIN sent over cleartext (encrypted by "speech"). I guess there is plenty of room for security on the backend.
It is more than fine for casual uses, but a serious user who publishes his phone number (payment address) would be subject to a really cheap attack by anyone who can look at his phone, or a somewhat cheap attack with the ability to reroute the phone, or a slightly cheap attack with local BTS spoofing.
It is more than fine for casual uses, but a serious user who publishes his phone number (payment address) would be subject to a really cheap attack by anyone who can look at his phone, or a somewhat cheap attack with the ability to reroute the phone, or a slightly cheap attack with local BTS spoofing.