Can you keep a backdoor 100% secret? Never brag, always be 100% secure in your use of it so that using it is untraceable. Never get sloppy, never make a mistake

Can you keep a backdoor 100% secret? Never brag, always be 100% secure in your use of it so that using it is untraceable. Never get sloppy, never make a mistake and be totally sure your private key can never ever be stolen? Even if you're sure you can do all that, do you think a government employee can? wants to? Is allowed to keep such things secret from colleagues? Will keep such secrets? Won't ever be hacked by a foreign power? It won't spill to his colleague with the gambling problem being compromised by <insert bogeyman here>? It won't be used in the future in ways that would still be considered non-kosher by the current NSA? The NSA can't keep their stuff safe from contractors who happen to be good guys with a conscience let alone bad guys being blackmailed. But I think he's talking more about appending a public ssh key to a something like router firmware authorized_keys file to be distributed to many devices.