Exactly. Using protocols to prevent double spending hurts performance and scalability. Detect fraudsters and ignoring them is cheap.
This is a fundamental issue I believe. If you have a stable legal ecosystem you can use the law of the land to ensure that double spending has real-world consequences. Preventing double spending is expensive. Guaranteed double spending _detection_ might also be sufficient and scales horizontally.
The "your papers please" argument. It's true. If you live in a world where you are compelled to present an identity for any financial transaction, then there is no need for bitcoin, to prevent double spending.
This requires permanent identities, right? So compared to cash payments, this system is potentially more oppressive because you can be rendered unable to pay for things.
I imagine there are some sticky legal questions to solve there - usually this kind of intervention in a person's life would require a court order or similar.
How traceable are transactions to the payer? Is there any anonymity?
Ignoring fraudsters will only work if that causes a cost to the fraudster bigger than the gain by double spending. Basically you will have to use key pairs tied to natural persons. If there is any anonymity or pseudonymity the fraudster will just generate a new key pair and double spend again. How does this system guard against that ?
we are building upon our own lightweight, scalable distributed ledger which has been in development for many years now. This ledger is based on the swift detection of double-spend behavior. You can find details on the fraud detection algorithm in our peer-reviewed paper, see https://dicg2020.github.io/papers/devos.pdf (an extended version is currently under review).
We have also performed scalability experiments on our nation-wide compute cluster to estimate the throughput of our distributed ledger. These experiments hint that our ledger is easily capable of handling 100.000+ transactions/sec.
This is a fundamental issue I believe. If you have a stable legal ecosystem you can use the law of the land to ensure that double spending has real-world consequences. Preventing double spending is expensive. Guaranteed double spending _detection_ might also be sufficient and scales horizontally.