On ios, you can get to the calculator while the system is still locked.

It was just an example.

You could use Guided Access to allow them to use the calculator without leaving the app.

"Then get yours out, you ain't touching my phone."

Easy to say when defending your point on Hacker News. We're already talking about security, and about someone with malicious intent having access to your phone. In the context of this conversation, you're already in simulated high security mental mode.

It's completely different when you're relaxed (maybe having some fun), and the person asking for your phone is someone you know.

In a relaxed social environment, you will probably not be that rude to someone you know.

I think the person you're responding to isn't familiar with relaxed social environments. Seriously, it's so hard to find empathy in security research.

> Seriously, it's so hard to find empathy in security research.

If I ever get a job in that sphere, I'll let you know.

> In a relaxed social environment, you will probably not be that rude

Perhaps I might phrase it slightly differently depending on who it was but the sentiment would be exactly the same[1] - a blanket refusal.

[1] Nowadays - back when I was on the Nokias or SE phones, sure, use my phone as a calculator, go nuts.

"Yes, but no, use your own."

No one has touched my phone while it was unlocked since middle school.

Most of the people have girlfriends and friends.

Believe me, it is possible to have a security-conscious, trustworthy girlfriend who respects your privacy if you do the same to her.

And I've never given my wife a single password or passcode or PIN. But she can still use my damn phone or computer if she wants, as can my friends. Worst case scenario, I get a 55 gallon drum of lube ordered on my Amazon account.

For me, the principle is I never divulge credentials, but I trust people I know. Therefore I see no conflict with adding my wife's fingerprint to TouchID, for example. (though it's not worth the effort of re-enrolling her every time I get a new device or a new screen or reinstall from scratch, so that's long lost).