The fiber record for quantum key distribution is 1,002 km, and satellites have linked ground stations about 12,900 km apart. The fiber record yields a few thousandths of a bit per second, and the satellite links depend on trusted relays. Here is what sets the limit and what changed in 2026.
Category: Quantum Communication
Eagle-1 QKD Satellite Launch Date: Why It Slipped to 2027–28
Europe’s first quantum key distribution satellite, Eagle-1, is now expected to launch at the end of 2027 or the beginning of 2028, about three years later than first planned. Here is what caused the delays, what the mission will test, and how its Dutch ground station is progressing.
E91 Protocol Explained: How Bell Tests Secure Quantum Keys
Artur Ekert’s 1991 E91 protocol turns entangled photon pairs and a Bell test into a shared secret key. This guide covers how it works, how it compares with BB84 and BBM92, and what experiments from Micius to 100 km device-independent QKD have shown.
Quantum Internet Explained: Repeaters, Teleportation, Real Links
A quantum internet distributes entanglement between distant nodes. It is not a faster internet. Here is how repeaters, teleportation and deployed-fiber links actually work, what has been demonstrated by 2026, and why it does not replace post-quantum cryptography.
BB84 Protocol Explained: How QKD Works and Where It Breaks
A step-by-step guide to the BB84 protocol: how two parties agree on a secret key with photons, why an eavesdropper leaves a 25% error rate, and which assumptions real systems have failed to meet.
NSA Still Won’t Back Quantum Key Distribution: The 2026 Rewrite
The NSA’s October 2026 rewrite of its QKD guidance keeps the 2020 verdict: no quantum key distribution for National Security Systems for now. Here is what stayed the same, what is new, and what it means for anyone choosing between QKD and post-quantum cryptography.