A new quantum cryptography scheme could enable unforgeable one-time signatures, and quantum money

[AntMan]

a futuristic piece of cryptography research landed this week. QPerfect and BTQ Technologies say they have engineered the first circuit level One Shot Signature scheme, bridging the gap between the cryptographic theory and something that can actually run as executable quantum circuits, using a framework they describe as local quantum cryptography

The mechanism is exotic, a quantum key generation and signing process that exploits quantum mechanics so a signature can only be used a single time, wrapped in dual layered program obfuscation for security. The claimed applications read like science fiction, trustless random beacons, secured one time token transfers, and the long theorised idea of genuine quantum money that physically cannot be copied

The context is that most quantum security news is defensive, everyone racing to post quantum encryption before a future machine breaks today's cryptography. This is the opposite, using quantum properties to build capabilities that are simply impossible classically, which is a more optimistic and much less discussed side of the same coin

So the discussion. Is offensive quantum cryptography, building genuinely new unforgeable primitives, a more exciting frontier than the defensive scramble to quantum proof our existing systems, or is this the kind of theoretically beautiful result that stays trapped in the lab for a decade because it needs fault tolerant hardware that does not yet exist?

News - Quantum Computing Reportquantumcomputingreport.com

[BrokenDave72]

Quantum money that physically cannot be copied is one of those ideas that sounds like nonsense until you understand the physics, the no cloning theorem makes it genuinely possible in a way no classical system can match, real magic

[BigDogShane10]

The catch is always the same, these schemes need reliable quantum hardware to hold and manipulate states, and today's machines cannot keep a state coherent long enough to be useful money, beautiful theory, no working coin yet

[Louise84]

That is the honest ceiling, one shot signatures are proven on paper and now demonstrated at circuit level, but circuit level on a simulator or a noisy device is a long way from a deployed system, still a real milestone though

[Ruby_50]

Offensive quantum crypto is way more interesting than the defensive scramble, post quantum encryption is just running to stay still, this is building things that were literally impossible before, that is the actual promise of the field

[Kieran_44]

Disagree on priority, the defensive work is boring precisely because it is urgent, harvest now decrypt later is a real threat today, quantum money is a delightful problem for a decade from now, sequence matters

[Dylan99]

Both matter but they are on completely different clocks, defensive crypto is a this decade necessity, offensive primitives like this are a next decade opportunity, calling either more exciting misses that they are barely the same field

[Ronan76]

The obfuscation layer is doing a lot of heavy lifting in that description and program obfuscation has a rocky theoretical history, I would want to see exactly what security assumptions this rests on before getting excited

[Rapid Crossing]

Trustless random beacons alone would be huge for everything from lotteries to blockchain consensus, a provably fair unpredictable random source is worth a fortune and notoriously hard to build classically, that application is underrated

[StoneCold_Mike]

BTQ acquiring QPerfect around the same time tells you they are serious about owning this whole stack, consolidating the theory and the hardware emulation under one roof is how you actually move something from paper to product