An Introduction to Quantum Computers and Quantum Cryptography - - PowerPoint PPT Presentation

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Nov 15, 2022 107 likes •228 views

An Introduction to Quantum Computers and Quantum Cryptography Computer Network Security Prepared by: Nima Bayan, P.Eng. Fall 2003 Contents ! Introduction " Cryptography and Relativity " Quantum Algorithms " Quantum Computers !

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An Introduction to Quantum Computers and Quantum Cryptography

Computer Network Security Prepared by: Nima Bayan, P.Eng. Fall 2003

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2 Quantum Computers Presentation, NB

! Introduction

"Cryptography and Relativity "Quantum Algorithms "Quantum Computers

! State of the art ! Applications ! Impact on cryptography ! Future of cryptography ! Suggested references

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Introduction: Cryptography and Relativity

! Cryptography helps when there are uncertain

transmission conditions (Passive and active attacks on the network)

" Receiver problem (eavesdropping) " Sender problem (masquerading) " Authenticity problem (Replay, Delay) " Traffic analysis

! Relativity Helps: A key part of Einstein’s special theory of

relativity

" It is impossible to send signals faster than speed of light " Use this to open two concurrent sessions for Alice and Bob

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Introduction: Quantum Algorithms vs. Classical Algorithms

! Classical Computers

" Alan Turing (1936)

! Classical computation

" Based on bits (0 or 1)

! Classical factoring

" Hard problems (NP)

! Classical search

" Bubble method (N/2)

! Quantum computers

" David Deutsch (1985)

! Quant. computation

" Based on qubits (0,1

and/or 0&1 !!!)

! Quant. factoring

" Peter Shor (1994)

! Quant. Search

" Amazing speed (√N) " Lov Grover

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Quantum Computers

! Make use of two

basic rules of quantum physics

" Superposition " Entanglement

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State of the art

! Quantum computers are built on the basis

f any quantic element

"Atom based QC (IBM 7 qubit computer) "Electron based QC (U of Cambridge, UK) "Photon based QCs

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State of the art

! IBM 7 qubit computer ! Dr. Chuang ! Fluorocarbon based ! Sequence of radio

pulses

! The atoms will

change into superposition state

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State of the art

! Quantum Gyroscopes

"Jonathan Dowling (NASA)

! Other applications ! Programming, ...

"Edward Farhi (MIT)

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Impact on cryptography

! Disadvantages

" All current hard problems

(RSA, ...) are not going to remain hard

" Using Shor’s method

! Advantages

" No intermediate

calculations

" New quantum based (more

bits more complex) algorithms

" Parallel sessions for Alice

and Bob

" Faster search routines " Faster factorizing

algorithms

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Suggested references

! General:

" http://www.qubit.org/ " http://www.cs.caltech.edu/~westside/quantum-intro.html " http://www.qubyte.com/ " http://computer.howstuffworks.com/quantum-computer.htm " http://physicsweb.org/article/world/15/4/4/1

! Programming languages for quantum computers

" http://tph.tuwien.ac.at/~oemer/qcl.html

! Quantum computers and cryptography

" http://en2.wikipedia.org/wiki/Quantum_computer " http://unisci.com/stories/20021/0215026.htm " http://www.qmechanics.supanet.com

! MIT’s Technology Review (March 2003) ! Spectrum (2002)