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Quantum Information Processing
Nicolas Gisin and Hugo Zbinden
GAP-Optique, University of Geneva
Quantum Computing
GAP Quantique
Quantum Key Distribution
Quantum Random Number Generators
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Quantum mechanics (all physics you need to know)
A particle can be at several locations
0
qubit = quantum bit
GAP Quantique
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• Likewise one can have
0 + 1 + 2 + 3 + ... + n
• 100 qubits can number all the particle there are
in the entire universe !
• Upon a measurement one single result shows up
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GAP Quantique
Computing
Process information: input x ⇒ output fct(x)
Quantum computer:
quantum processing of classical information
input 0 + 1 + 2 + ... + n ⇒ fct (0) + fct (1) + fct (2) + ... + fct (n)
A measurement can provide only one result
This single result can provide information about
a global property of the function fct.
For example, the maximum value, the mean
value, or information about the periodicity of
the function.
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Fact
GAP Quantique
Period of a function + a bit of number theory
⇒ break all of today’s public key cryptographic
i.e. allows one to decipher all encrypted
messages
Hence, a quantum computer will render today’s
public key cryptography obsolete
RSA is finished
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What happens if RSA is gone?
GAP Quantique
All electronic money loses instantaneously all
value
An enormous economic crisis, compared to
which 2008 will look like a pleasant joke
All encrypted messages can be deciphered
retroactively
Our information based society rests on an
enormous bet: the bet that RSA will not be
broken!
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GAP Quantique
Our society rests on an enormous bet:
the bet that RSA will not be broken!
The bet is likely to be lost
A mathematician could find an efficient
algorithm to break RSA
This could happen in a century or tomorrow
Nobody knows when it will happen, but most
specialist agree that it is likely to happen
someday (though some disagree)
Everybody agrees that a quantum computer
will break RSA
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When shall we have a
quantum computer ?
GAP Quantique
I bet in 10 years
Note that 5 years ago I was betting on 20 years.
Seems things are accelerating.
My bet is based on the tremendous progress
and investments in superconducting qubits
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GAP Quantique
The Quantum computer is
around the corner
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GAP Quantique
In 10 years Google, NSA, etc will
know all our secrets
All governmental, financial , industrial, health
etc, secrets encoded with RSA will be readable.
Not only future secrets, but also today’s secrets.
Indeed, all encrypted messages send today are
registered and will be available in clear format.
⇒ if you want your secrets to hold for a decade,
it is already too late.
⇒ you better change your crypto infrastructure
as soon as possible.
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How soon do we need to worry?
Depends on:
How long do you need encryption to be secure?
(x years)
How much time will it take to re-tool the existing
infrastructure with large-scale quantum-safe
solution? (y years)
How long will it take for a large-scale quantum
computer to be built (or for any other relevant
advance? (z years)
GAP Quantique
Theorem 1: If x + y > z, then worry.
What do we do here??
y
x
z
time
Courtesy of Prof. Michele Mosca
There are only two alternatives
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1. In 10 years I will be retired, hence do nothing.
2. Act today.
What to do ? ⇒ Quantum Safe Cryptography.
• Make a new bet, betting on a new problem
believed to be hard.
• Exploit the gifts of nature and base future
cryptography on quantum physics:
Quantum Key Distribution (QKD).
The only solution proven to be robust
against a quantum computer.
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Integrated QKD system
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Future:
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Integration into ATCA blades
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Standard telecom format
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N. Walenta et al, “A fast and versatile quantum key distribution system with hardware
key distillation and wavelength multiplexing,” New J. Phys. 16, 013047 (2014)
Secret key rates
Optimum detector
temperature found
for each fiber length
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Trade off between
dark counts and
afterpulsing
GAP Quantique
3.2 bits/s at 307 km
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B. Korzh, C. W. Lim et al., “Provably Secure and Practical Quantum Key Distribution over
307 km of Optical Fibre,” arXiv1407.7427 (2014)
Short distance, high rate QKD
Work by Toshiba:
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Decoy state BB84 protocol
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Self-differencing detectors
Over 1 Mbps
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GAP Quantique
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Enough for video live
video call encryption
with One-Time Pad
M. Lucamarini et al, “Efficient decoy-state quantum key distribution with quantified
security” , Opt. Express 24551 (2013)
L. C. Comandar et al, “Room temperature single-photon detectors for high bit rate
quantum key distribution” , Appl. Phys. Lett. 104, 021101 (2014)
N. Walenta et al, “Sine gating detector with simple filtering for low-noise infra-red single photon
detection at room temperature” , J. Appl. Phys. 112, 063106 (2012)
Example of a commercial link running
continuously since 2011
67 km
GAP Quantique
Installed multiplexed quantum
channel for commercial users.
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WDM: multiplex the Quantum and
≈ 109 timeson
more
intense
!!!
Classical channels
a single
fiber
GAP Quantique
QBER = QBERopt + QBERdet + QBERnoise/WDM
What are the noise sources?
• Crosstalk of other wavelengths into quantum channel
• Generation of parasitic light at the wavelength of the Q channel
• by Raman scattering (dominant for lengths > 10 km)
• by Four Wave Mixing (FWM)
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Field Trial of Multiplexed QKD/10G Data (Toshiba)
GAP Quantique
Four forward 10G channels
Data rate = 40 Gb/s (error free)
QKD key rate = 160 kb/s.
Key failure probability = 10-10.
Two forward , two backward 10G
Data rate = 40 Gb/s (error free)
QKD key rate = 110 kb/s.
Key failure probability = 10-10
Choi et al, Opt Ex. 22,2014 (2014)
Quantum Network Using Existing Solutions
GAP Quantique
Eventually, a point-topoint network becomes
impractical.
GAP Quantique
Quantum Network Architecture With Trusted Node
QKD Trusted Node
Keys move securely across
the network in a piece-wise
fashion
GAP Quantique
Coherent One-Way (COW) Protocol
Telecom-compatible architecture (ATCA)
Up to 8 quantum blades per chassis
FIPS 140-2 Certification (Planned)
CC Evaluation (Planned)
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Long Range QKD with trusted nodes
Battelle QKD Backbone
• Columbus OH to Washington
DC Area
• > 770 km
• Deployment targeted in 2015
GAP Quantique
≈ 800 km
Battelle
Aberdeen Office
Battelle Main Campus
North American Quantum Network
Our goal – a network
of nodes that can be
used as the basis for
secure network
across North America
GAP Quantique
(and the rest of the
world!)
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Korean government plan
[ Quantum R&D Testbed(~’15)]
[ National Administrative Network ~‘20)]
Seoul
: Regional Network
: Backbone
Bundang
Suwon
SKT(Bundang) – KIST(Suwon) – NSTR(Seoul)
[ Quantum Backbone(~’17)]
Seoul
GAP Quantique
Southern
Gyeonggi
Tentative the number of nodes
Category
Sejong
Daejeon
Seoul-Southern Gyeonggi-Sejong-Daejeon
Public
Administration
Prosecutor &
Police Office
Post Office
# of node
비고
347
National wide office
2,264
National wide office
3,562
National wide office
Extend to defense and financial institute
- Defense comm.: 516 nodes
- Financial Institute(1tier) 8275 nodes(incl. branches)
Quantum Backbone
Chinese Trusted Node
Quantum Network
Based on trustable relay, setting up “Quantum Backbone”
GAP Quantique
Hefei
Shanghai
Jinan
Beijing
ChineseBackbone
Trusted node Quantum network
Quantum
Total Length 2000 km
2013.6-2016.12
32 trustable relay nodes
Beijing
31 fiber links
Metropolitan networks
Jinan
Existing: Hefei, Jinan
New: Beijing, Shanghai
GAP Quantique
Total Investment: 560 M
RMB. Half by NDRC, Half by
Local government
Customer: China Industrial &
Hefei
Commercial Bank; Xinhua
News Agency; CBRC
Shanghai
Future
Chinese Trusted node Quantum network
Ulumuqi
GAP Quantique
Hefei
Shanghai
Jinan
Beijing
GAP Quantique
Mind your Random Number Generator!
Advantages
• Truly random process
produces truly random sequences
• Simple process that can be modelled
influence of environment can be ruled out
• Live monitoring of elementary components
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Quantum Random Number Generator
Detectors
Photons
4 cm
Semi-transparent
Mirror
GAP Quantique
Source of photons
4 Mb per second of balanced random bits
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Evaluation and Certification
Non-Deterministic (Physical) RNG
• PTG.1
Physical RNG with internal tests that
detect a total failure of the entropy source
and non-tolerable statistical defects of the
internal random numbers
• PTG.2
GAP Quantique
PTG.1, additionally a stochastic model of
the entropy source and statistical tests of
the raw random numbers
• PTG.3
PTG.2, additionally with cryptographic
post-processing (hybrid PTRNG)
Conclusions
GAP Quantique
Quantum Computer is already today a serious thread
to standard cryptography.
Not taking this fact seriously would
lead to a devastating economical crisis.
Solutions exist.
B
Quantum Key Distribution is a possible solution.
ei
Today QKD is limited to point to point,
ji
Ji
but developments by several key players
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will son make QKD networks with trusted g
a
nodes available.
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H
ef
ei
Sh
Trusted Random Number Generators is
an
gh
another urgent need.
Quantum Random Number Generator is an existingai
solution.
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Winter school 2015
7th Winter school on practical quantum communications
January 18th to January 22th 2015
In Les Diablerets, Switzerland
Keynote speakers
– Whitfield Diffie
– Nicolas Gisin
– Dr. Colin P Williams, D-Wave,
– Sandu Popescu
– Eleni Diamanti
– …
Website:
www.idquantique.com/instrumentation/training
Contact: [email protected]
GAP Quantique
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Further reading :
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GAP Quantique
Proposals for quantum communication in
space
Dual-downlink
(ROM R&D 47 M€)
Single-uplink
(ROM R&D 1 M€)
GAP Quantique
Using a motorized
photo-lens-pod (existing)
and a dedicated quantum
detector as “camera”.
Simultaneous
optical downlink:
1400 km separation.
R. Ursin et al., Europhysics News,
26-29, 40–40 (3) (2009)
T. Scheidl, E. Wille, and R. Ursin,
New Journal of Physics, 15, 043008 (2013)
[email protected] - Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences
Astronaut:
A. Kuipers
There is nothing like cracking QKD !
The principle of QKD will never be attacked,
only the implementation may be faulty.
GAP Quantique
The implementation must be checked, as is the case
for all hardware and all software.
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Bit rate of the 1st transatlantic telegram
GAP Quantique
How long did it take to transmit this congratulation in 1858 ?
"The Queen desires to congratulate the President upon the
successful completion of this great international work, in which
the Queen has taken the deepest interest. The Queen is convinced
that the President will join with her in fervently hoping that the
electric cable, which now connects Great Britain with the United
States, will prove an additional link between the two places whose
friendship is founded upon their common interests and reciprocal
esteem. The Queen has much pleasure in thus directly
communicating with the President, and in renewing to him her
best wishes for the prosperity of the United States."
17 hours ! (1 letter took 2 minutes)
http://www.itelegram.com/telegram/Atlantic_Cable_150.asp
http://epe.lac-bac.gc.ca/100/205/301/ic/cdc/cable/fmessages.htm
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