But the entire thread is about delegating the authentication, granting access to another machine or process. You want to give access to one device (e.g. TV) from the trusted one (e.g. iPhone).
Both devices might be very pricey, real, up-to-date machines with TPM and keys and everything you want. The problem is that you can't tell whether the TV is the one TV that the iPhone's owner means to sign in.
Both devices might be very pricey, real, up-to-date machines with TPM and keys and everything you want. The problem is that you can't tell whether the TV is the one TV that the iPhone's owner means to sign in.