Highway (CBC Casper) Algorithm | cryptocurrencies, blockchains & live prices

Highway is the consensus protocol used by the Casper Network, based on the CBC (Correct-by-Construction) Casper family of consensus protocols originally researched by Vlad Zamfir. Highway extends the CBC Casper framework with a practical protocol design that enables validators to reach consensus by building a DAG of protocol messages. Validators produce blocks and endorsements (called "ballots") that reference previous messages, forming a growing DAG structure. The protocol uses a "summit" detection mechanism — validators independently analyze the DAG to determine when enough validators have expressed support for a particular block, at which point it is considered finalized. Highway allows validators to operate at different speeds (ticking rates), which is where the name comes from — like cars on a highway driving at different speeds.

Highway provides flexible finality, where the time to finality can be tuned based on the desired level of security. The protocol achieves Byzantine fault tolerance, guaranteeing safety as long as fewer than one-third of validators by weight are Byzantine. The heterogeneous timing model — where validators can operate at different rates — is a distinctive feature that accommodates real-world conditions where validators have different hardware capabilities and network connections. Faster validators produce blocks more frequently, contributing more to throughput, while slower validators still participate in consensus at their own pace. This design improves both inclusivity and overall network performance compared to protocols that force all validators into a uniform timing schedule.

Highway has been running on the Casper Network mainnet since March 2021. Casper was founded by Mrinal Manohar and Medha Parlikar and developed by CasperLabs, with Vlad Zamfir serving as an early advisor based on his CBC Casper research at Ethereum. The Casper Network is designed for enterprise adoption, featuring upgradeable smart contracts (a distinctive feature) and a developer-friendly environment. The network uses a proof-of-stake model where validators bond CSPR tokens. Casper has targeted enterprise and government use cases, with various partnerships in the Middle East and other regions focused on bringing blockchain technology to traditional institutions.