Quantum Cryptography: Assessing Technological Advancements and the U.S. Landscape

Quantum computing will eventually break the public-key cryptography that secures global communications, financial systems, and national security infrastructure today. The United States government has chosen post-quantum cryptography (PQC), new mathematical algorithms, as its primary response to this new threat, with federal agencies mandated to complete migration by 2035. A 2020 advisory by the National Security Agency (NSA) advisory declined to approve quantum key distribution (QKD), a hardware-based alternative whose security rests on the laws of physics rather than mathematical assumptions, citing five technical limitations. This report assesses the current state of the transition of quantum cryptography and the evolving role of QKD in the U.S. landscape.

The geostrategic stakes are significant. The U.S.–China Economic and Security Review Commission has warned that leadership in quantum technologies will confer asymmetric advantages in intelligence and economic competitiveness. Research indicates that China currently has an edge in the field of quantum communication and thus quantum cryptography, as the country operates the world’s most extensive quantum communication network, has demonstrated a 3,700 km integrated QKD network, and is now also exporting quantum computing technology. The guidance by the NSA, meanwhile has meant that most of the government’s efforts in transitioning to quantum-safe networks have been directed at PQC. As the report notes, there are indications that some progress has been made against each of the NSA’s five objections. Furthermore, the U.S. private sector continues to pursue QKD technologies and research.

Other countries are also continuing to pursue research efforts and business development in the QKD space, while simultaneously also working on the short-term implementation of PQC standards. Japan, for example, has carved out a unique position in QKD-related research. Many of its leading technology firms, such as Toshiba and NEC have developed significant capabilities in this regard. Furthermore, the country is well-positioned to cooperate with U.S. firms and the public sector on quantum computing, with the October 2025 U.S.–Japan Technology Prosperity Deal calling for bilateral collaboration on quantum networks and Beyond 5G/6G technologies. Many countries in Europe and the European Union (EU) itself are also continuing to pursue a dual-track approach of implementing PQC, while researchers and companies further develop QKD technologies. While PQC thus remains the near-term priority in the United States and among many American allies and partners, there are thus some indications listed in this report, that a hybrid PQC–QKD approach may be feasible for the most sensitive applications in specific sectors in the future.

publication details

• Authors:

  Peter Sparding

• Publication date:

  April 2026

• Pages:

  38