Yes, security is the key factor with this project.
Several times I found myself abandoning a site while browsing on my mobile because I had to provide a private key in the login process.
And even if HiveSigner was supported, I didn't have my HiveSigner password handy, or I had to enter the private active key, which I never provided to any website, even the HiveSigner page.
I feel way safer now with this new solution.