Physicists at Harvard University have built what they believe is the world’s longest secure quantum communications network using 22 miles of currently existing fiber-optic cables.

The experiment, published in the scientific journal Nature, connected two functional quantum computer nodes to each other through a strange physical phenomenon called “entanglement.” This allowed them to share data across the 22-mile distance in a paradigm that, according to the laws of physics, is unhackable.

Q-Day

The world is currently embroiled in a technological race to shore up global computer security ahead of “Q Day,” a hypothetical point in the near future when bad actors will have access to quantum computers powerful enough to shred current encryption methods.

While major institutions such as banks, military installations and the healthcare industry have already begun adopting protocols to protect data, there currently exists no functional replacement for data transmission.

Essentially, no matter how well-encrypted data is, any time it is transmitted, there’s a risk of unwanted interception.

Quantum computers and quantum networking have the potential to eliminate this risk due to the nature of how quantum data is handled.

Quantum networking

Data cannot be copied in a quantum system. This is because quantum data is extremely brittle. The slightest permutation, including something as innocuous as performing a simple scientific measurement, changes the data, rendering it unusable. 

Since quantum data can’t be copied, it cannot be transmitted from one node to another in the traditional sense. Instead, it must be “entangled,” at both points. This is accomplished using diamonds with a specific kind of flaw at their “hearts” that allows scientists to exploit a vacuum space to entangle quantum information.

Simply put, quantum mechanics allows for the teleportation of data but not the transmission.

Because of this, the big fear isn’t that bad actors will build quantum systems to intercept data — we could be decades away from even the most well-funded adversarial organizations having access to quantum systems — but that legacy data, encrypted with nonquantum protections, will be stolen from today’s systems and transmissions and then stored for decryption at a later date when bad actors can find some way to access a modern quantum computer system.

In the meantime, the experimental quantum network systems being built today could one day serve as the primary medium for the distribution of sensitive data.

Rather than, for example, sending financial transaction information through the typical banking “wires,” or legacy networks, institutions could store data in well-protected data centers and only “send” it to other institutions or stakeholders via quantum entanglement, where there’s absolutely no chance of hacking.

This could have massive implications for the decentralized finance community, as the idea of “owning” data could be upended by a paradigm where access is inextricably confined to entangled nodes. In this way, it’s conceivable that digital assets such as cryptocurrency could be secured against all forms of network-based attacks.

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