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You either store the keys centrally, or use a weaker encryption strategy. Those are the only ways to decrypt something. Either one makes it easier for anybody t
by _bxg1 8y ago
You either store the keys centrally, or use a weaker encryption strategy. Those are the only ways to decrypt something. Either one makes it easier for anybody to hack.
The classic metaphor is that of a castle wall. If you put a gate in it, no matter how well your fortify that gate, it remains a weak point compared to the rest of the wall.
- tzs 8y ago> You either store the keys centrally, or use a weaker encryption strategy. Those are the only ways to decrypt something. Either one makes it easier for anybody to hack. That was right before 1973. The development of public key cryptography in 1973 adds another option. Take the symmetrical key the device uses to encrypt user data and encrypt a copy of that key using a public key of the entity that the back door is for. The authorized back door user can decrypt that copy using their private key. If the public key system parameters are chosen correctly anyone else trying to get in who does not have a copy of that private key faces a problem at least as hard as brute forcing the underlying device encryption.
- chopin 8y agoHow do you secure the private key?
- _bxg1 8y agoThey still hold a copy of their own private key somewhere, you're just punting the issue a little bit. Plus, there would have to be a single key for all users, or you'd have to give every user's key to the institution as well. That means more travel over the wire, that means central storage of skeleton keys, etc. Each of these factors introduces another vector of possible attack. If there's a gate, there's a way to get in, and no matter how many keys are required or where they're kept, they'll always be more vulnerable than a wall with no gate.