The Unbreakable Line Still Cannot Beat the Speed of Light

SINGAPORE — The most common question Dr. Wei-Lin Tan of the Singapore Institute fields is also the most persistent misunderstanding: whether Q-Net, the quantum-secured backbone that has carried the world's unbreakable encryption since 2110, can somehow send a message faster than light. It cannot, and Tan spends much of her public life saying so. "Entanglement secures the channel," she told a room of engineering students this week. "It does not carry the words. The words still travel the ordinary way, at the ordinary speed." The distinction matters most on the longest link the network serves: the run to the Mars colonies at Valles Marineris, where the one-way delay this month sits near fourteen minutes and only widens as the planets separate. No quantum trick shortens it. What Q-Net guarantees, Tan said, is that in those fourteen minutes no one else can read the message — a smaller promise than the myth, and a truer one.