Zayo announced yesterday that it has sold some dark fiber to Quantum Xchange on the east coast. Quantum Xchange is working on a national network to power its Quantum Key Distribution network, which leverages new techniques from quantum mechanics to encrypt and decrypt messages.
The purchase includes 530 route miles between Boston and Washington DC along Zayo's existing network footprint. The idea is to physically transfer a shared photonic key between locations. If someone tries to get that key to eavesdrop on communications using it, quantum entanglement would let both sides know that security is breached. This is one of those cases where the potential capacity offered by dark fiber isn't really what anyone cares about, it's solely about the connectivity.
Such networks have been cropping up on a small scale in research settings, and a few commercial attempts are underway in Europe and Asia. This seems to be one of the first in the US, and is worth keeping an eye on. The first customers may be the financial guys, who do always like to be on the bleeding edge of networking.
The fear in the security sector is that quantum computing will make it possible to break the encryption methods we depend non so much in today's world. QKD is billed as a possible replacement, at least in particularly sensitive cases. If it takes off, we're definitely going to see more deals like this.