Semi-device-independent security of one-way quantum key distribution

Understand

By testing nonlocality, the security of entanglement-based quantum key distribution (QKD) can be enhanced to being 'device-independent'.

• Here we ask whether such a strong form of security could also be established for one-way (prepare and measure) QKD.
• While fully device-independent security is impossible, we show that security can be guaranteed against individual attacks in a semi-device-independent scenario.
• In the latter, the devices used by the trusted parties are non-characterized, but the dimensionality of the quantum systems used in the protocol is assumed to be bounded.