"Lawful interception for devices, but no backdoors"
Interception is a fucking back door! It's an alternative way to make encryption useless. It's like having a heavy duty front door and deadbolt but leaving the key under the welcome mat.
More like leaving the key in the lock with a PLB (personal locator beacon for emergency) a flashing strobe light with a 120 decibel siren as a fob.