Solana Replaces Tower BFT and Proof of History with Alpenglow Protocol
Solana infrastructure firm Anza has proposed a new consensus upgrade called Alpenglow to boost speed and finality.
Alpenglow uses Votor and Rotor to cut transaction finality to 150 milliseconds and reduce reliance on timestamping.
Anza, an independent infrastructure firm formed out of Solana Labs, has introduced a major protocol overhaul for the Solana network. The new proposal, dubbed Alpenglow, aims to transform Solana’s proof-of-stake consensus system and potentially position it as a contender to existing Web2 infrastructure.
1/ Introducing the largest Solana Protocol change ever: Alpenglow, Solana’s new consensus protocol conceived by the Anza Research team. Say goodbye to Tower BFT and Proof of History. Say hello to Votor & Rotor pic.twitter.com/KPNQxQ1jBg
— Anza (@anza_xyz) May 19, 2025
Revealed on May 19 by Anza researchers Quentin Kniep, Kobi Sliwinski, and Roger Wattenhofer, Alpenglow introduces a dual-layer architecture that replaces core elements of Solana’s current framework. The developers called it the most significant shift to Solana’s protocol since its inception.
At the heart of Alpenglow are two components: Votor, a consensus mechanism for validating and finalizing blocks, and Rotor, a data transmission protocol designed to replace Solana’s signature proof-of-history system. Together, these elements aim to significantly cut the time it takes for network nodes to reach an agreement on transaction finality.
Targeting Sub-Second Finality With Votor and Rotor
Alpenglow’s architecture is engineered to deliver finality in about 150 milliseconds, a latency that could place Solana in direct competition with mainstream internet infrastructure. According to Anza, achieving such responsiveness could unlock real-time blockchain use cases in finance, gaming, and communication — sectors where delays of even a few seconds can be disruptive.
Votor is set to replace Solana’s current TowerBFT consensus, operating through two parallel voting paths. The protocol finalizes a block in a single round if at least 80% of stake-holding validators respond. If only 60% are responsive, a second round ensures finality. This dual-mode design allows Votor to maintain performance even under degraded network conditions.
Rotor complements this setup by eliminating the reliance on cryptographic timestamping used in proof-of-history. Instead, it focuses on rapid, verifiable data propagation between validators, which enables consensus without sequential timekeeping.
Anza’s researchers argue that combining these two components can deliver “unprecedented finalization latency,” significantly improving responsiveness without sacrificing security. Such performance, they claim, could position Solana as a leader in high-throughput, low-latency blockchain applications.
Limitations and Solana’s Path to Resilience
Despite the ambitious scope of the upgrade, Anza acknowledged that Alpenglow will not solve all of Solana’s technical challenges. Notably, the network’s history of outages stems from a lack of client diversity. Currently, Solana relies heavily on Agave — its sole production-ready validator client. Any critical vulnerability within Agave presents a systemic risk to network stability.
However, client diversity is set to improve. A new validator client, Firedancer, developed independently, is expected to launch on Solana’s mainnet later in 2025. Once deployed, it will provide an alternative execution path and improve the network’s overall fault tolerance.
Golden Cross Pattern Sparks Bullish Momentum for Solana
While the protocol upgrade draws attention, SOL’s market performance is also under close watch. The token is holding firm above $168 after breaking resistance near $167. Technical charts suggest a potential golden cross is forming—where the 21-day EMA crosses above the 200-day EMA—a move often seen as a bullish signal.
Source: Trading View
Solana’s price is currently testing the 200-day EMA, a level that traders consider a major support zone. Trading volume has increased by 132% in the past 24 hours, pointing to rising interest among investors. If SOL maintains this level and breaks above $172, a move toward $180 and potentially $192 could follow.
However, failure to hold above $165 could signal weakness. Support exists at $162 and, in a sharper pullback, at $150. The market remains range-bound for now, and a breakout above $172 or a drop below $165 is likely to determine the next trend.
Filed under: Bitcoin - @ May 21, 2025 11:21 am