The future of quantum cryptography BCS Meeting 17th Sept 2009 J. G. Rarity University of Bristol john.rarity@bristol.ac.uk
Summary Commercial systems. Metro Networks. Future long range key exchange. Consumer key generation Spin-off. The prospect of a factoring machine
Off the shelf systems 40K 40K idquantique (www.idquantique.com www.idquantique.com) system: 100km link guaranteed 1000 secure keybits per second Plug and play Other commercial systems from: Smartquantum: www.smartquantum.com MagiQ: www.magiqtech.com Development systems: Toshiba, NTT AS YET ALL SYSTEMS REQUIRE DARK FIBRE for QUANTUM LINK
Certification Common Criteria CC EAL4 Incorporating AES encryptor systems Certification to CC EAL4 XOR quantum key with public key distributed private keys
Quantum cryptography metro networks: Boston, Vienna, Geneva www.secoqc.net
Long Range Key exchange: now to 250km using Coherent one-way protocol (COW) using Corning ultra-low loss fibres
The quantum repeater Entangled pair generator Entangled pair generator Correlation With Bob photons Repeater = Bell measurement= Compares photons Correlation with Alice photons Throughput is always limited by attenuation of entire channel Requires a quantum memory
Entanglement based quantum communication over 144km. R. Ursin, et al quant-ph/0607182, Nature Physics 3 481, 2007 144km key exchange
ESA OGS 1 metre telescope (Bob)
ISS to ground QKD A quantum terminal onboard the ISS is capable of transmission of faint laser pulses to 1 ground station transmission of faint laser pulses to 1 ground station transmission of single photons to ground stations (to one at a time) distribution of entangled photon pair to 2 separate ground stations reception of single photons (uplink) Possible Scenarios Single link to ground Maximum distance Spacecraft- OGS:1800km Double link to ground Maximum distance OGS-OGS: OGS: 1400 km Link availability statistics will be presented by Mr. Baister in the next talk 10
Quantum non-locality from space, global key exchange
Short range low cost systems for consumer applications
The PROBLEM Most rapidly growing fraud is card not present fraud How do we protect our on-line transactions The SOLUTION: Bringing quantum secured key exchange to the consumer Could use one-time-pad to protect the PIN Generate one-time-pad using quantum secured key exchange Key exchange at ATM allows user to top-up a personal one-time-pad. Protects against skimming
Pictures of the present handheld system < 3000 < 10 Key exchange at ATM allows user to top-up a personal one-time-pad. Protects against skimming One time pad encoding of PIN protects online transactions
Alice unit drive electronics and optics LED s Beam combiner Polariser Pinholes Pulse shortening circuit and diode driver Alice Optics
Future FPGA/DSP Alice unit (2 yrs) ASIC single chip $1-10 100MHz pulse rates to give ~1Mbit keys in 100ms Millimetre cubed Alice optics unit, (?waveguides, credit card?) Miniature low cost Random number generator (RNG) Fully tested low cost time tagging instrument Rapid alignment without cradle?
Why is it unique: Weekly top-up a personal one-timepad into a personal phone/card. Protects against skimming Type your PIN into YOUR device Absolute security for PIN online Eventually low cost, free to all customers The competition At home: present readers provide simplistic security based on toy codes. In shops: data between the card and reader isn t encrypted during a transaction and the PIN is sent in the clear! (See http://www.cl.cam.ac.uk/~sd410/)
Spin-off technologies near market instrument flexible photon counting instruments based on FPGA technology True random number generators Photon counting detectors
Far Futures: the threat of quantum computing Quantum technologies could revolutionise computing, sensing and communications in the 21 st century: Exponential speed up of computing using single quanta atoms, electrons, ions, photons as Qubits. Spintronics with individual spins. Ultrasensitive magnetometry: sensing of single spins in surfaces through their effect on a single spin in an AFM tip. Sub-wavelength scale measurement and lithography.
An integrated CNOT gate realised in Silica on Silicon Politi et al: Science 320, 647, 2008. Shor s Factoring Algorithm on a Photonic Chip: Politi et al et al Science 325, 1221 (Sept 2009) Established fabrication technology for classical communication systems at 1.55 um wavelength
Future proof systems Where will QC be used: Medical records Government secrets Any data that needs to remain secret for some time Cost competitive systems Consumer systems Simplified schemes Back up in case of development of polynomial factoring Quantum computer Classical algorithm
Thankyou: now lets discuss
Bob detector unit
Alice unit schematic
FPGA based time tag unit
Overview of system
Transfer matrices between Alice and Bob
Error rate and secret bit rate as a function of background light