I was reading about the security design behind Fabric Protocol last night around 10:15 working on my laptop. I thought its approach to Byzantine Fault Tolerance was very interesting.
I think this model is necessary to keep decentralized network working even when some nodes don't do what they're supposed to. 
Byzantine Fault Tolerance keeps the network running smoothly, even when some folks act out or just disappear. Looking at how the system works, I really get why trustless security matters so much for Web3.
What I like most about Fabric’s security model? It’s all about stability and bouncing back from trouble.