quantum cryptography - luhome.lu.lv/~sd20008/papers/slides/quantum_cryptography.pdf · quantum...
TRANSCRIPT
![Page 1: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/1.jpg)
QuantumCryptography
Māris OzolsUniversity of Cambridge
![Page 2: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/2.jpg)
Overview
● What are quantum computers?● What is quantum cryptography?
- Shor's algorithm for factoring- Quantum key distribution- Device-independent quantum cryptography
![Page 3: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/3.jpg)
What is quantum computing?
Physics Computer
Science
Mathematics
QuantumComputing
![Page 4: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/4.jpg)
Quantum mechanics
![Page 5: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/5.jpg)
How to simulate quantum physics?
Simulating quantum systems on a regular computer is very hard...
Wouldn't it be easier if the computer itself would operate based on the laws of quantum physics?
Richard Feynman
![Page 6: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/6.jpg)
What is a quantum computer?
Quantum mechanics
Quantum computer is a device that processes information by using quantum phenomena
+
Computer
![Page 7: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/7.jpg)
What quantum computers are not...
![Page 8: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/8.jpg)
justsmaller
What quantum computers are not...
![Page 9: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/9.jpg)
justsmaller
What quantum computers are not...
justfaster
![Page 10: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/10.jpg)
justsmaller
What quantum computers are not...
exponentiallyfaster
justfaster
![Page 11: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/11.jpg)
justsmaller
What quantum computers are not...
exponentiallyfaster
justfaster science
fiction
![Page 12: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/12.jpg)
justsmaller
What quantum computers are not...
exponentiallyfaster
justfaster
availablefor $ale
science fiction
![Page 13: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/13.jpg)
Quantum cryptography
● Quantum algorithms for breakingexisting cryptosystems- Shor's algorithm for factoring
![Page 14: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/14.jpg)
Quantum cryptography
● Quantum algorithms for breakingexisting cryptosystems- Shor's algorithm for factoring
● Enabling secure communication- Quantum key distribution
![Page 15: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/15.jpg)
Quantum cryptography
● Quantum algorithms for breakingexisting cryptosystems- Shor's algorithm for factoring
● Enabling secure communication- Quantum key distribution
● Computation with untrusted devices- Device-independent quantum cryptography
![Page 16: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/16.jpg)
Multiplying vs factoring
3 × 5 = 1511 × 13 = 143
28423087481 × 25162321141 = 715190855015658735821
Multiplying is easy...
![Page 17: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/17.jpg)
Multiplying vs factoring
3 × 5 = 1511 × 13 = 143
28423087481 × 25162321141 = 715190855015658735821
Multiplying is easy...
![Page 18: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/18.jpg)
Multiplying vs factoring
12 = 3 × 4377 = 13 × 29
57249035862524887649 = 2543563837 × 22507410677
3 × 5 = 1511 × 13 = 143
28423087481 × 25162321141 = 715190855015658735821
Multiplying is easy...
Factoring is not...
![Page 19: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/19.jpg)
Multiplying vs factoring
12 = 3 × 4377 = 13 × 29
57249035862524887649 = 2543563837 × 22507410677
3 × 5 = 1511 × 13 = 143
28423087481 × 25162321141 = 715190855015658735821
Multiplying is easy...
Factoring is not...
![Page 20: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/20.jpg)
Public-key cryptography (RSA)
![Page 21: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/21.jpg)
Public-key cryptography (RSA)
Public key57249035862524887649
Private key254356383722507410677
![Page 22: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/22.jpg)
Public-key cryptography (RSA)
Public key57249035862524887649
Private key254356383722507410677
Message
Encrypt
![Page 23: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/23.jpg)
Public-key cryptography (RSA)
Public key57249035862524887649
Private key254356383722507410677
Message
Encrypt
Decrypt
Message
![Page 24: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/24.jpg)
Shor's algorithm breaks RSA
Peter Shor
● Produces prime factors of a given integer● Runs in polynomial time
(best known classical algorithm runs in exponential time)
![Page 25: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/25.jpg)
Shor's algorithm breaks RSA
Peter Shor Fourier transform of Peter Shor
● Produces prime factors of a given integer● Runs in polynomial time
(best known classical algorithm runs in exponential time)● Based on quantum Fourier transform
![Page 26: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/26.jpg)
Quantum key distribution
![Page 27: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/27.jpg)
Quantum key distribution
Uncertainty principle
Quantum system cannot beobserved without disturbing it
![Page 28: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/28.jpg)
Quantum key distribution
![Page 29: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/29.jpg)
Device-independent quantum cryptography
untrusted device
![Page 30: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/30.jpg)
Device-independent quantum cryptography
test
testtesttest
computetesttest
untrusted device
Strategy 1: Self-testing
![Page 31: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/31.jpg)
Device-independent quantum cryptography
test
testtesttest
computetesttest
untrusteddevice 2
test
testtesttest
computetesttest
untrusteddevice 1
Strategy 2: Cross-checking
![Page 32: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/32.jpg)
Device-independent quantum cryptography
Device-independent quantum protocols exist for● quantum key distribution● randomness expansion● randomness amplification
test
testtesttest
computetesttest
untrusteddevice 2
test
testtesttest
computetesttest
untrusteddevice 1
![Page 33: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/33.jpg)
Long-term implications
Security vs Privacy
![Page 34: Quantum Cryptography - LUhome.lu.lv/~sd20008/papers/slides/Quantum_cryptography.pdf · Quantum mechanics Quantum computer is a device that processes information by using quantum phenomena](https://reader034.vdocument.in/reader034/viewer/2022050312/5f743b6aef6fba1a1f7783d8/html5/thumbnails/34.jpg)
Thank you!