| From their FAQ: > Can I backup my private key? > Backing up your private key reduces its security to the security of the backup. We do not currently support backing up or extracting your private key. In the future we may add key splitting among team members or transferring your private key directly to a new phone. All my data that the private key would be protecting access to is backed up, so I've ALREADY bought in to the idea that my security is bounded by the security of my backups. It is not clear to me that not letting me back up the private key actually does anything to help my security. In fact, it may weaken it. Their FAQ says that if I lose my phone what I'm supposed to do is remove my public key from all my accounts, get a new phone, install Kypton on it, generate new keys, and put the new public keys on my accounts. To do this, I have to have a way to access those accounts without using my private key. That means my security is bounded by the security of my non-Krypton access method. If my non-Krypton access method is strong, that means I've got to be set up to deal with strong non-Krypton secret management...but if I have to do that anyway what do I need Krypton for? I can just manage my primary access method secrets myself too. Also, what if the site requires two factor for the alternate access method? I'm probably going to be using my phone for that...but remember we're talking here about the case where I lose my phone, so I lose both my primary access (Krypton) and my secondary. |
From "Other uses for Touch ID and Face ID" in https://www.apple.com/business/docs/iOS_Security_Guide.pdf
"App developers can do the following: [...] Generate and use ECC keys inside Secure Enclave that can be protected by Touch ID or Face ID. Operations with these keys are always performed inside the Secure Enclave once it authorizes their use."
edit: This page has more details https://krypt.co/docs/security/privacy-policy.html