BT's Pathway to Quantum

The quantum age heralds transformative advancements in secure communication. To protect against the looming threat of quantum computers to digital security, two complementary avenues are being explored - Quantum Key Distribution (QKD) and Post Quantum Cryptography (PQC).  QKD offers security by leveraging quantum mechanics to securely exchange cryptographic keys, while PQC shows potential robustness against quantum attacks by developing classical public key cryptographic algorithms. Entangled photon networks promise ultra-secure communication channels and are hoped to eventually enable quantum networks that distribute quantum information between quantum processors, using quantum teleportation. Progress has been made in the last five years, and the risk of large scale cryptographically relevant quantum computers (CRQCs) within the next decade is significant. In response to this, we expect a phase of rapid adoption of technologies to protect the confidentiality and security of critical systems and communications, such as all-symmetric key based cryptography, QKD and PQC. In the medium term, these technologies will mature and be widely adopted. Long-term, entangled photon networks may revolutionize global communication, achieving unparalleled quantum computation, security, and efficiency – and novel use-cases in quantum cryptography beyond QKD. Operators must navigate these evolving technologies to future-proof communication systems.