One aspect of biometrics - mostly fingerprints, I'll admit - that I don't see discussed very often is the issue of injury, (Note, this is based entirely on my own personal experience with a particular device several years ago, and may not generalise, but I think the general idea is valid).
Let's say I locked my phone with my thumbprint. But then I hurt my thumb chopping vegetables or mountain-climbing or whatever, and for a few days it's wrapped in a bandage to stop myself bleeding all over the place. But that means that in that time it's that much harder to unlock my phone. Yes, in theory you can use your other thumb, if prints are the same across digits (are they? I'm not sure - I know my phone was twitchy at the best of times and definitely didn't work), but that can be awkward switching hands etc. And what if - and this is quite niche - the injury is sufficient to permanently change your print, due to scarring or something? And that's on top of the demonstrated issues if your hands are dirty or wet or whatever.
You'd need some kind of backup, which is fine, but then you just have another potential weakness since any system is only as secure as its weakest point.
I'm not saying biometrics are useless. It's totally plausible that for most people, most of the time, they're a strong improvement in both security and convenience - I haven't done the research on that topic. But I rarely see that view discussed. Maybe because it's not actually a major issue, I don't know.
One aspect of biometrics - mostly fingerprints, I'll admit - that I don't see discussed very often is the issue of injury, (Note, this is based entirely on my own personal experience with a particular device several years ago, and may not generalise, but I think the general idea is valid).
Let's say I locked my phone with my thumbprint. But then I hurt my thumb chopping vegetables or mountain-climbing or whatever, and for a few days it's wrapped in a bandage to stop myself bleeding all over the place. But that means that in that time it's that much harder to unlock my phone. Yes, in theory you can use your other thumb, if prints are the same across digits (are they? I'm not sure - I know my phone was twitchy at the best of times and definitely didn't work), but that can be awkward switching hands etc. And what if - and this is quite niche - the injury is sufficient to permanently change your print, due to scarring or something? And that's on top of the demonstrated issues if your hands are dirty or wet or whatever.
You'd need some kind of backup, which is fine, but then you just have another potential weakness since any system is only as secure as its weakest point.
I'm not saying biometrics are useless. It's totally plausible that for most people, most of the time, they're a strong improvement in both security and convenience - I haven't done the research on that topic. But I rarely see that view discussed. Maybe because it's not actually a major issue, I don't know.