I also share the opinion that the threat model is flawed, biased. You define it "deep dive" but you didn't even scratch the surface of the issue. > At the core

I also share the opinion that the threat model is flawed, biased. You define it "deep dive" but you didn't even scratch the surface of the issue. > At the core, phone operating systems are built with better sandboxing than their desktop counterparts. This is why security experts like Matt Green recommend phones for your most sensitive data. Having a better sandboxing is not the same as having a "safe sandboxing". How secure is the application once an attacker is able to compromise the sandboxing? IMHO the rest of the threat model "deep dive" has no value once we take that attack scenario into account. What about a non-dictionary based 20chars password protecting your private key, or storing your SSH key on an OpenPGP Smartcard in a USB token, a Yubikey or a Nitrokey (www.nitrokey.com)? I believe that it would be much more secure than application whose security model is based on the sole sandboxing.