Casper is powered by the Rust programming language, uses WebAssembly for a virtual machine, and has a proprietary consensus protocol called Highway. The Highway protocol offers flexibility with respect to the configuration of security thresholds among nodes running the protocol, allowing nodes with lower thresholds to reach finality faster than the ones requiring higher levels of confidence. Thanks to Highway, Casper reaches higher thresholds of finality, while still living in a partially synchronous Byzantine Fault Tolerant (BFT) model.