techcrunch | A new — and theoretical — system for blockchain-based data storage
could ensure that hackers will not be able to crack cryptocurrencies
once the quantum era starts. The idea, proposed by researchers at the
Victoria University of Wellington in New Zealand, would secure
cryptocurrency futures for decades using a blockchain technology that is
like a time machine.
You can check out their findings here.
To
understand what’s going on here we have to define some terms. A
blockchain stores every transaction in a system on what amounts to an
immutable record of events. The work necessary for maintaining and
confirming this immutable record is what is commonly known as mining.
But this technology — which the paper’s co-author Del Rajan claims will make up “10 percent of global GDP… by 2027” — will become insecure in an era of quantum computers.
Therefore
the solution to store a blockchain in a quantum era requires a quantum
blockchain using a series of entangled photons. Further, Spectrum
writes: “Essentially, current records in a quantum blockchain are not
merely linked to a record of the past, but rather a record in the past,
one that does not exist anymore.”
Yeah, it’s weird.
From the paper intro:
Our method involves encoding the blockchain into a temporal GHZ (Greenberger–Horne–Zeilinger) state of photons that do not simultaneously coexist. It is shown that the entanglement in time, as opposed to an entanglement in space, provides the crucial quantum advantage. All the subcomponents of this system have already been shown to be experimentally realized. Perhaps more shockingly, our encoding procedure can be interpreted as non-classically influencing the past; hence this decentralized quantum blockchain can be viewed as a quantum networked time machine.
In short, the quantum
blockchain is immutable because the photons that it contains do not
exist at the current time but are still extant and readable. This means
the entire blockchain is visible but cannot be “touched” and the only
entry you would be able to try to tamper with is the most recent one. In
fact, the researchers write, “In this spatial entanglement case, if an
attacker tries to tamper with any photon, the full blockchain would be
invalidated immediately.”
Is this possible? The researchers note that the technology already exists.
