Solana's Anza Introduces Alpenglow Protocol for 150ms Finality

Anza, a blockchain infrastructure firm that was spun out from Solana Labs, has introduced a new proof-of-stake consensus protocol called Alpenglow. This protocol is described as the most significant change to Solana’s core protocol to date, with the potential to compete with existing internet infrastructure. The proposal was made by Anza’s Quentin Kniep, Kobi Sliwinski, and Roger Wattenhofer on May 19.

Alpenglow consists of two main components: Votor and Rotor. Votor handles voting transactions and block finalization logic, while Rotor is a data dissemination protocol designed to replace Solana’s proof-of-history timestamping system. The goal of Rotor is to reduce the time it takes for all nodes to agree on the network state. Anza researchers claim that Alpenglow could achieve actual finality in about 150 milliseconds, making Solana’s responsiveness comparable to Web2 infrastructure. This could open up new possibilities for blockchain applications that require real-time performance.

Votor, which would replace the current TowerBFT system, is designed to finalize blocks in a single round if 80% of the stake is participating, and in two rounds if only 60% of the stake is responsive. These two voting modes operate concurrently, with finalization occurring as soon as the faster path completes. Anza’s researchers assert that this model would result in unprecedented finalization latency, allowing the network to function more effectively under challenging conditions.

Despite the potential benefits of Alpenglow, the transition to this new protocol is not expected to completely eliminate Solana’s network outages. The project’s white paper acknowledges that Solana’s reliance on a single production-ready client, Agave, means any security vulnerability in Agave could disrupt the entire network. To mitigate this risk, a new independent validator client called Firedancer is set to launch on Solana’s mainnet later this year. This development aims to provide client diversification, enhancing the overall security and stability of the Solana ecosystem.