This is good if your threat model doesn't include the phone itself. I built something simliar to this as an external hardware implementation a few years back t

This is good if your threat model doesn't include the phone itself. I built something simliar to this as an external hardware implementation a few years back to deal with the phone itself being rooted: https://www.anomie.tech/products/anigma/ https://www.anomie.tech/products/anigma/ Been working towards getting it ready for open source release later this year.. password manager, two factor auth, and message encryption accomplished in the external hardware, was the core idea.