Book contents
- Frontmatter
- Contents
- Foreword
- Introduction
- Acknowledgments
- 1 Probability basics
- 2 Probability distributions
- 3 Measuring information
- 4 Entropy
- 5 Mutual information and more entropies
- 6 Differential entropy
- 7 Algorithmic entropy and Kolmogorov complexity
- 8 Information coding
- 9 Optimal coding and compression
- 10 Integer, arithmetic, and adaptive coding
- 11 Error correction
- 12 Channel entropy
- 13 Channel capacity and coding theorem
- 14 Gaussian channel and Shannon–Hartley theorem
- 15 Reversible computation
- 16 Quantum bits and quantum gates
- 17 Quantum measurements
- 18 Qubit measurements, superdense coding, and quantum teleportation
- 19 Deutsch–Jozsa, quantum Fourier transform, and Grover quantum database search algorithms
- 20 Shor's factorization algorithm
- 21 Quantum information theory
- 22 Quantum data compression
- 23 Quantum channel noise and channel capacity
- 24 Quantum error correction
- 25 Classical and quantum cryptography
- Appendix A (Chapter 4) Boltzmann's entropy
- Appendix B (Chapter 4) Shannon's entropy
- Appendix C (Chapter 4) Maximum entropy of discrete sources
- Appendix D (Chapter 5) Markov chains and the second law of thermodynamics
- Appendix E (Chapter 6) From discrete to continuous entropy
- Appendix F (Chapter 8) Kraft–McMillan inequality
- Appendix G (Chapter 9) Overview of data compression standards
- Appendix H (Chapter 10) Arithmetic coding algorithm
- Appendix I (Chapter 10) Lempel–Ziv distinct parsing
- Appendix J (Chapter 11) Error-correction capability of linear block codes
- Appendix K (Chapter 13) Capacity of binary communication channels
- Appendix L (Chapter 13) Converse proof of the channel coding theorem
- Appendix M (Chapter 16) Bloch sphere representation of the qubit
- Appendix N (Chapter 16) Pauli matrices, rotations, and unitary operators
- Appendix O (Chapter 17) Heisenberg uncertainty principle
- Appendix P (Chapter 18) Two-qubit teleportation
- Appendix Q (Chapter 19) Quantum Fourier transform circuit
- Appendix R (Chapter 20) Properties of continued fraction expansion
- Appendix S (Chapter 20) Computation of inverse Fourier transform in the factorization of N = 21 through Shor's algorithm
- Appendix T (Chapter 20) Modular arithmetic and Euler's theorem
- Appendix U (Chapter 21) Klein's inequality
- Appendix V (Chapter 21) Schmidt decomposition of joint pure states
- Appendix W (Chapter 21) State purification
- Appendix X (Chapter 21) Holevo bound
- Appendix Y (Chapter 25) Polynomial byte representation and modular multiplication
- Index
- References
20 - Shor's factorization algorithm
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Foreword
- Introduction
- Acknowledgments
- 1 Probability basics
- 2 Probability distributions
- 3 Measuring information
- 4 Entropy
- 5 Mutual information and more entropies
- 6 Differential entropy
- 7 Algorithmic entropy and Kolmogorov complexity
- 8 Information coding
- 9 Optimal coding and compression
- 10 Integer, arithmetic, and adaptive coding
- 11 Error correction
- 12 Channel entropy
- 13 Channel capacity and coding theorem
- 14 Gaussian channel and Shannon–Hartley theorem
- 15 Reversible computation
- 16 Quantum bits and quantum gates
- 17 Quantum measurements
- 18 Qubit measurements, superdense coding, and quantum teleportation
- 19 Deutsch–Jozsa, quantum Fourier transform, and Grover quantum database search algorithms
- 20 Shor's factorization algorithm
- 21 Quantum information theory
- 22 Quantum data compression
- 23 Quantum channel noise and channel capacity
- 24 Quantum error correction
- 25 Classical and quantum cryptography
- Appendix A (Chapter 4) Boltzmann's entropy
- Appendix B (Chapter 4) Shannon's entropy
- Appendix C (Chapter 4) Maximum entropy of discrete sources
- Appendix D (Chapter 5) Markov chains and the second law of thermodynamics
- Appendix E (Chapter 6) From discrete to continuous entropy
- Appendix F (Chapter 8) Kraft–McMillan inequality
- Appendix G (Chapter 9) Overview of data compression standards
- Appendix H (Chapter 10) Arithmetic coding algorithm
- Appendix I (Chapter 10) Lempel–Ziv distinct parsing
- Appendix J (Chapter 11) Error-correction capability of linear block codes
- Appendix K (Chapter 13) Capacity of binary communication channels
- Appendix L (Chapter 13) Converse proof of the channel coding theorem
- Appendix M (Chapter 16) Bloch sphere representation of the qubit
- Appendix N (Chapter 16) Pauli matrices, rotations, and unitary operators
- Appendix O (Chapter 17) Heisenberg uncertainty principle
- Appendix P (Chapter 18) Two-qubit teleportation
- Appendix Q (Chapter 19) Quantum Fourier transform circuit
- Appendix R (Chapter 20) Properties of continued fraction expansion
- Appendix S (Chapter 20) Computation of inverse Fourier transform in the factorization of N = 21 through Shor's algorithm
- Appendix T (Chapter 20) Modular arithmetic and Euler's theorem
- Appendix U (Chapter 21) Klein's inequality
- Appendix V (Chapter 21) Schmidt decomposition of joint pure states
- Appendix W (Chapter 21) State purification
- Appendix X (Chapter 21) Holevo bound
- Appendix Y (Chapter 25) Polynomial byte representation and modular multiplication
- Index
- References
Summary
This chapter describes what is generally considered to be one of the most important and historical contributions to the field of quantum computing, namely Shor's factorization algorithm. As its name indicates, this algorithm makes it possible to factorize numbers, which consists in their decomposition into a unique product of prime numbers. Other classical factorization algorithms previously developed have a complexity or computing time that increases exponentially with the number size, making the task intractable if not hopeless for large numbers. In contrast, Shor's algorithm is able to factor a number of any size in polynomial time, making the factorization problem tractable should a quantum computer ever be realized in the future. Since Shor's algorithm is based on several nonintuitive properties and other mathematical subtleties, this chapter presents a certain level of difficulty. With the previous chapters and tools readily assimilated, and some patience in going through the different preliminary steps required, such a difficulty is, however, quite surmountable. I have sought to make this description of Shor's algorithm as mathematically complete as possible and crack-free, while avoiding some academic considerations that may not be deemed necessary from any engineering perspective. Eventually, Shor's algorithm is described in only a few basic instructions. What is conceptually challenging is to grasp why it works so well, and also to feel comfortable with the fact that its implementation actually takes a fair amount of trial and error. The two preliminaries of Shor's algorithm are the phase estimation and the related order-finding algorithms.
- Type
- Chapter
- Information
- Classical and Quantum Information TheoryAn Introduction for the Telecom Scientist, pp. 399 - 430Publisher: Cambridge University PressPrint publication year: 2009