Quantum key distribution promises ultra-secure communication by using the strange rules of quantum physics to detect eavesdroppers instantly. But even the most secure quantum link can falter if the transmitter and receiver aren’t perfectly aligned. Researchers have now taken a deep dive into this often-overlooked issue, building a powerful new analytical framework to understand how tiny beam misalignments—caused by vibrations, turbulence, or mechanical flaws—disrupt secure key generation.
