Practicality of Deploying and Managing Quantum Networks.pdf

1、From point-to-point to multi-tenanted QKD networksPracticality of Deploying and Managing Quantum NetworksPaul Wright,Optical and Quantum Networks Research Manager,BT UKPracticality of Deploying and Managing Quantum NetworksSPECIAL FOCUS:QUANTUMSECURITYWhat is Quantum Key Distribution?QKD distributes

2、 encryption keys by encoding information on streams of photons of light that is impossible to hack during transmission and provides secrecy immune to computational advances Encryption keys are formed out of a stream of single photonsPhotons carry keys using phase,polarization,or position modulationT

3、he key is refreshed constantlyQKD system performance is measured using:Secure Key rate keys per secondQBER quantum bit error ratePerformance of QKD is affected by:Distance/LossNoise(e.g.co-existence with other channels)But quantum physics laws mean we cannot amplify quantum signals classically(known

4、 as the no-cloning theorem)Reach of Quantum SystemsSecure key rate vs fibre length measured(symbols)on the Toshiba LD QKD system,along with the calculated dependence(solid line)From Toshiba Whitepaper Realising Scalable QKD NetworksTrusted NodeReads the quantum state,processes it classically and gen

5、erates a new quantum state to forward onMust be in trusted locations secure racks in secure roomsAchievable with todays technologyA solution for specific tasks such as QKD,not practical for more complex generic quantum computationQuantum RepeaterUses quantum entanglement to teleport the quantum stat

6、e between the endpoints No need for intermediate nodes in trusted locationsStill in the research phase Allows more complex quantum operations(such as entanglement swapping)to extend the untrusted range of QKDExtending the Reach of Quantum SystemsMulti-layer modelEach incoming QKD link to a trusted n