Letter 1

  Background 5

  Quantum Computers Pose Significant Threats to Cryptography on Federal Systems 12

  Agencies Have Not Fully Implemented Preparatory Practices for Addressing Quantum Cyber Threats 20

  Conclusions 33

  Recommendations for Executive Action 34

  Agency Comments and Our Evaluation 34

Appendix I Objectives, Scope, and Methodology 37

Appendix II Summary of China’s Efforts to Prioritize Quantum Information

Science Development 45

Appendix III Summary of National Quantum Computing Cybersecurity Strategy 48

Appendix IV Comments from the Department of Homeland Security 51

Appendix V Comments from the Social Security Administration 53

Appendix VI GAO Contact and Staff Acknowledgments 54