Quantum Computation and Cryptography

Mentor: Andru Gheorghiu gheorghiuandru@gmail.com


Quantum mechanics is one of the most successful and, at the same time, counter-intuitive theories in physics. Initially, research into quantum mechanics was primarily concerned with explaining phenomena as they are observed in nature. This then led to a flurry of technological developments ranging from nuclear energy to lasers, all of which make use of quantum mechanical effects. Recently, however, a new direction has emerged that seeks to use these quantum effects for computation, information processing, communication and cryptography.

Quantum computation came with the realization that algorithms operating on quantum systems could be used to break many of today's cryptographic protocols (such as RSA, Diffie-Hellman, El Gamal, Eliptic Curve Cryptography and others) by efficiently solving the hard problems on which those protocols are based (factoring, computing the discrete logarithm). But quantum computers would also have other uses, such as allowing us to efficiently simulate complex quantum systems (with applications to physics, chemistry, medicine and materials science), performing machine learning tasks, as well as more abstract applications. This has motivated a substantial investement in quantum computing research, a fact that has become apparent especially in the last few years. Small scale quantum computers have already been made available online, from IBM and Rigetti, and larger devices are soon to follow.

While quantum computers have the potential to disrupt the existing cybersecurity infrastructure, one solution comes in the form of quantum cryptography. This allows for the design of cryptographic protocols (for key distribution, random number generation and delegated computation among others) whose security is based on the fundamental laws of physics, rather than computationally hard problems. Commercial quantum crypto devices have been around for some time and recently quantum cryptography has taken to space, with the launch of the first satellite enabling secure quantum communication.

This workshop aims to give a general introduction into these topics and to convey the new thinking, excitement and challenges that go with quantum information science.

If you want to know more about quantum information research in Romania check out the Romanian Quantum Network (RoQnet) or contact Dr. Radu Ionicioiu (r.ionicioiu@theory.nipne.ro) and Dr. Mona Mihailescu (mona.mihailescu@physics.pub.ro).


At the end of the workshop you should be familiar with:

  • How quantum information is represented and processed
  • Elementary quantum algorithms and the principles behind them
  • The basics of quantum cryptography
  • Approaches to post-quantum cryptography
  • The basics of quantum hardware (the physical implementation of quantum technologies)
  • Elements of fault tolerant quantum computation

When and Where?

Dates: Aug 20th - Aug 24th
Times: 7pm-9pm
Location: Universitatea Politehnica Bucuresti, cladirea PRECIS
Room: PR001


  1. Monday, 20 Aug
    • Introduction: A brief history of quantum computation and quantum cryptography, what makes them interesting and the current state of the art. Slides here.
    • What's quantum about quantum computing?: A simple explanation of what makes quantum special and why quantum algorithms could outperform classical algorithms at certain tasks. Slides here.
  2. Tuesday, 21 Aug
    • How to make a physical theory 101: We'll discuss the core elements that characterize a physical theory, how these apply to quantum mechanics and how this takes us to quantum information. Slides here.
    • Quantum information basics: Qubits and quantum gates and how to use them to make quantum algorithms. We'll also look at a simple quantum computation on the IBM quantum chip. Slides here.
  3. Wednesday 22 Aug
    • Quantum algorithms: Continuing with algorithms, we'll look at the quantum algorithms of Simon and Shor. Slides here.
    • Post-quantum cryptography: Given that Shor's algorithm compromises the security of many public-key crypto protocols, we'll discuss a potential fix, namely post-quantum cryptography. Slides here.
  4. Thursday, 23 Aug
    • Quantum cryptography: An introduction to quantum cryptography and the BB84 quantum key distribution protocol. Slides here.
    • Entanglement and device-independence: We'll see how quantum entanglement allows us to have secure protocols even in the presence of untrusted quantum devices, or so-called device-independent protocols. Slides here.
  5. Friday, 24 Aug
    • Quantum hardware: How do we physically realize qubits and quantum gates? A look at the basics of quantum hardware. Slides here.
    • Fault tolerance and the future: We end by discussing how quantum devices can cope with noise and imperfections as well as discuss the outlook for future implementations. Slides here.


It is recommended that you are familiar with the basics of:

  • Complex numbers
  • Vector spaces and linear algebra
  • Probability theory

Ideally you should be able to answer these questions, or at the very least be familiar with the concepts addressed by those questions.


Registration is closed.

sesiuni/quantum-cryptography.txt · Last modified: 2018/09/02 20:11 by agheorghiu