The Hidden Subgroup Problem: Lecture 17 of Quantum Computation at CMU

The Hidden Subgroup Problem: Lecture 17 of Quantum Computation at CMU

🎙 Ryan O'Donnell 👥 14K 📅 November 3, 2018 ⏱ 83 min 👁 5K 📄 lecture 🧭 2026-08-17
Available in: English (current) Français

Keywords

Hidden Subgroup Problemquantum algorithmgroup theoryFourier transformcryptography

Summary

This lecture from Carnegie Mellon University’s Quantum Computation course introduces the Hidden Subgroup Problem (HSP) as a unifying framework for several known quantum algorithms. The instructor, Ryan O’Donnell, begins by reviewing previous algorithms: Bernstein-Vazirani, Simon’s problem, period finding, and Shor’s algorithm, showing how each fits into the HSP framework. He then formally defines groups, subgroups, and cosets, and states the HSP for any group. The lecture discusses the known results: for abelian groups, the HSP is efficiently solvable by quantum computers, leading to applications like factoring and discrete logarithms. For non-abelian groups, the problem is largely open, with the dihedral group being a notable example with potential applications to lattice problems and post-quantum cryptography. The instructor also mentions a result by Ettinger, Hoyer, and Knill showing that the quantum Fourier sampling provides enough information to solve the HSP in principle, but no efficient classical post-processing is known. The lecture concludes with a discussion of open problems and the importance of HSP in quantum computing.

164 words

Critical Evaluation

Value of the Information & Strength of the Argument

The lecture provides a comprehensive and well-structured overview of the Hidden Subgroup Problem, synthesizing multiple quantum algorithms into a single framework. The argumentation is clear and logical, building from specific examples to a general formulation. The instructor effectively explains the mathematical concepts of groups and cosets, making the material accessible to students with a background in linear algebra. The discussion of applications, particularly in cryptography, highlights the practical significance of the problem. The lecture also honestly addresses the limitations and open questions in the field, providing a balanced perspective.

Scientific Rigor, Source Quality, Title Accuracy

The lecture is scientifically rigorous, with precise definitions and references to known results. The instructor cites specific algorithms and theorems, such as Shor’s algorithm and the Ettinger-Hoyer-Knill result, without providing external sources. The title accurately reflects the content, which is a focused lecture on the Hidden Subgroup Problem. The lecture is part of a formal university course, indicating a high level of academic rigor. The description includes links to the course website and discussion board, which are relevant for further study.

185 words

Title / Content Match

The title accurately reflects the content, which is a lecture on the Hidden Subgroup Problem.

Quality & Reliability

9/10

Lecture by a recognized expert in theoretical computer science, part of a formal university course. Content is mathematically rigorous, with clear definitions and references to known results. No obvious errors or unsupported claims.

Key Moments

Cited Sources

  • Course website — Course materials and lecture notes.
  • Weekly work — Problem set for the lecture.
  • Panopto — Video platform used for recording.
  • Diderot discussion board — Course discussion platform.

Concurring Sources

Contribution & Novelties

This lecture provides a clear and comprehensive introduction to the Hidden Subgroup Problem, unifying several quantum algorithms under a single framework. It is particularly valuable for its pedagogical approach, building from simple examples to the general problem, and for its discussion of open problems and applications in cryptography.

Pour aller plus loin :

92 words

Radar Profile

The radar profile shows high scores across all dimensions, indicating a lecture that is both information-dense and technically rigorous. The balance between theoretical depth and practical applications is well maintained.

Reliability 9/10