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.