3 ms·
But the same applies to the messages themselves, no? QKD is only for key exchange, so I assume the resulting keys themselves are just random (non-quantum) bits
by bsza 5y ago
But the same applies to the messages themselves, no? QKD is only for key exchange, so I assume the resulting keys themselves are just random (non-quantum) bits of data, and the encrypted messages are sent through plain old TCP/IP. If a message is intercepted, the same tactics of waiting until the encryption is no longer secure could work.
- dandanua 5y agoI thought about the scenario when some old secret key is revealed. Sure, you can decrypt old messages with it if they were transmitted classically. But in a classical channel if you're capturing all the traffic then you can derive the current secret key and decrypt current messages as well. This is not possible in a quantum case.
- bsza 5y agoWhat if you store a large number of keys on the module right from the start, and get all the new keys from that list. That way the key switch message only needs to contain the index of the new key. Even better, store a huge random seed and generate all subsequent keys from that. Then you can also change key size and algorithm as needed without ever having to meet your contact in person again.