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Shor's algorithm in Quantum Cryptography
Nwaokocha, Martyns ; Vašík, Petr (oponent) ; Hrdina, Jaroslav (vedoucí práce)
Cryptography is a very important aspect of our daily lives as it gives the theoretical foun-dation of information security. Quantum computation and information is also becoming avery important field of science because of its many application areas including cryptologyand more specifically in public key cryptography.The difficulty of numbers into its prime factors is the basis of some important publickey cryptosystems key of which is the RSA cryptosystem. Shor’s Quantum factoring al-gorithm leverages most especially the quantum interference effect of quantum computingto factor semi-prime numbers in polynomial time on a quantum computer. Though thecapacity of current quantum computers to execute the Shor’s Algorithm is very limited,there are many extensive foundational scientific research on various techniques of opti-mizing the algorithm in terms of factors such as number of qubits, depth of the circuitand number of gates.In this thesis, various variants of the Shor’s factoring algorithm and quantum circuits arediscussed, analysed and compared. Also, some variants of the Shor’s algorithm are simu-lated and actually executed on simulators and quantum computers in the IBM QuantumExperience platform. The simulation results are compared in terms of their complexityand success rate.The organization of the thesis is as follow: Chapter 1 discusses some key historical resultin quantum cryptography, states the problem discussed in this thesis and presents the ob-jectives to be achieved. Chapter 2 summarizes the mathematical background in quantumcomputing and public key cryptography as well as describing the notation used through-out the thesis. This also explains how a realizable order-finding or factoring algorithmcan be used to break the RSA cryptosystem. Chapter 3 presents the building blocks ofShor’s algorithm including the Quantum Fourier Transform, Quantum Phase Estimation,Modular Exponentiation and Shor’s algorithm in detail. Different optimization variantsof the quantum circuits are also presented and compared here. Chapter 4 presents theresults of the simulations of the various versions of the Shor’s algorithm. In Chapter 5, wediscuss the achievement of thesis goals, summarize the results of the research and outlinepossible future research directions.
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Kvantové aplikace založené na platformě IBM QX
POLÁK, Josef
Tato bakalářská práce se snaží přiblížit a objasnit fungování kvantové informatiky. První část práce objasňuje základy kvantové mechaniky, které je nutné znát pro pochopení následujících základů kvantové informatiky. V těchto základech jsou objasněný výrazy jako kvantový bit, kvantové logické brány a mnohé další vlastnosti kvantového světa (pozitivní i negativní). Pro představu jsou uvedeny i nejznámější algoritmy, které jsou založené na kvantových výpočtech. Další z cílů práce je přiblížit a seznámit platformu IBM QX. Na té se lze seznámit s kvantovými obvody a spustit vlastní kvantové obvody na kvantových počítačích sdílených na cloudu. Poslední částí je vývoj aplikace řešící problém obchodního cestujícího. Byl vybrán algoritmus, který funguje na klasickém počítači. Poté byl zapojen kvantový výpočet do algoritmu pro urychlení. Nakonec následovala tvorba uživatelského rozhraní. Aplikace spíš ukazuje fungování kvantových výpočtů, než že by mohla být použitelná v praxi. Po přepracování by bylo možné využit v logistice.
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Shor's algorithm in Quantum Cryptography
Nwaokocha, Martyns ; Vašík, Petr (oponent) ; Hrdina, Jaroslav (vedoucí práce)
Cryptography is a very important aspect of our daily lives as it gives the theoretical foun-dation of information security. Quantum computation and information is also becoming avery important field of science because of its many application areas including cryptologyand more specifically in public key cryptography.The difficulty of numbers into its prime factors is the basis of some important publickey cryptosystems key of which is the RSA cryptosystem. Shor’s Quantum factoring al-gorithm leverages most especially the quantum interference effect of quantum computingto factor semi-prime numbers in polynomial time on a quantum computer. Though thecapacity of current quantum computers to execute the Shor’s Algorithm is very limited,there are many extensive foundational scientific research on various techniques of opti-mizing the algorithm in terms of factors such as number of qubits, depth of the circuitand number of gates.In this thesis, various variants of the Shor’s factoring algorithm and quantum circuits arediscussed, analysed and compared. Also, some variants of the Shor’s algorithm are simu-lated and actually executed on simulators and quantum computers in the IBM QuantumExperience platform. The simulation results are compared in terms of their complexityand success rate.The organization of the thesis is as follow: Chapter 1 discusses some key historical resultin quantum cryptography, states the problem discussed in this thesis and presents the ob-jectives to be achieved. Chapter 2 summarizes the mathematical background in quantumcomputing and public key cryptography as well as describing the notation used through-out the thesis. This also explains how a realizable order-finding or factoring algorithmcan be used to break the RSA cryptosystem. Chapter 3 presents the building blocks ofShor’s algorithm including the Quantum Fourier Transform, Quantum Phase Estimation,Modular Exponentiation and Shor’s algorithm in detail. Different optimization variantsof the quantum circuits are also presented and compared here. Chapter 4 presents theresults of the simulations of the various versions of the Shor’s algorithm. In Chapter 5, wediscuss the achievement of thesis goals, summarize the results of the research and outlinepossible future research directions.
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