3 ms·
QKD does defend against active man-in-the-middle. Working from the premise that qubits in general cannot be cloned (the no-cloning theorem), a protocol can be d
by praseodym 8y ago
QKD does defend against active man-in-the-middle. Working from the premise that qubits in general cannot be cloned (the no-cloning theorem), a protocol can be devised that can detect tempering by an adversary with unlimited computational power and technological abilities. BB84[1] is such a protocol, which is also used in commercial QKD products.
Of course it doesn’t defend against attacks on the devices, buildings or people; these are likely higher ranked risks than crypto attacks for many organisations.
[1]: https://en.wikipedia.org/wiki/BB84 https://en.wikipedia.org/wiki/BB84
- nneonneo 8y agoI think OP's point is that no key establishment protocol - quantum or otherwise - protects against a true "man-in-the-middle" who can simply negotiate different keys with both parties and transparently decrypt-encrypt in the middle. Of course, this isn't what QKD is supposed to solve, anyway. QKD does not address authentication, only key distribution.