Espresso Systems Upgrades Testnet Decaf to Permissionless Proof-of-Stake Model

Espresso Systems announced on April 25 an upgrade of the Decaf testnet for its Espresso Network to a permissionless proof-of-stake (PoS) consensus mechanism. This significant milestone advances Espresso Network's path toward full decentralization.

Espresso is designed as a confirmation layer to enable cross-chain interoperability within the Ethereum network. Since launching its mainnet in November 2024, it has operated under a permissioned system, involving participation from 100 nodes across six continents and 22 institutional and community operators. With the Decaf upgrade, the network has transitioned to a permissionless environment, allowing broader participation.

Espresso Foundation highlighted this development in a tweet:

"Espresso's Decaf testnet now runs on proof-of-stake!
This marks an important milestone on our journey to unite Ethereum’s fragmented L2/L3 ecosystem with a fast, secure & decentralized interop layer.
Mainnet PoS + $ESP token launch coming soon."

Mainnet Rollout and ESP Token Launch Slated for 2025

Espresso identifies this upgrade as the final rehearsal before its mainnet release, anticipated in 2025. The mainnet, referred to as "Mainnet 1," will introduce ESP, a native token to support governance and economic security.

Enhanced Block Finality and Optimized Network Performance

The Decaf upgrade involves more than a consensus shift; it includes significant network improvements. Espresso Systems optimized block finality through its HotShot consensus algorithm, reducing block finalization from four rounds to three.

Additionally, enhancements to the Verifiable Information Dispersal (VID) protocol allow nodes to process data more efficiently. By using an erasure coding-based shard distribution system, nodes no longer need to download entire blocks, increasing network efficiency.

Espresso Systems reports that these upgrades led to an average block confirmation time reduction of approximately 29% in tests, which they anticipate will enhance communication speeds across Ethereum's Layer 2 (L2) and Layer 3 (L3) chains.

Preparing for Mainnet and Expanding Participation

During this testing phase, the network's existing 22 node operators have been allocated staking shares in Decaf. Following further testing, Espresso plans to extend staking delegation to new operators. Interested node operators can apply through Espresso Systems' documentation.

In the coming weeks, Espresso Systems will update its official channels, including X (formerly Twitter) and Discord, with announcements regarding Mainnet 1 rollout timelines, ESP token launch details, and onboarding processes for new operators. A staking delegation program will be introduced to recognize and reward current node operators' contributions.

Addressing Ethereum Fragmentation Through Decentralized Interoperability

Espresso Systems aims to address the fragmentation challenges within Ethereum's L2 and L3 ecosystems. The network uses a Byzantine Fault Tolerance (BFT) consensus model to enable fast and reliable cross-chain communication, achieving transaction trust and usability in seconds.

The Decaf upgrade marks a pivotal step toward uniting Ethereum's ecosystem layers, aligning with Espresso’s mission.

Espresso Foundation reiterated this vision:
"Espresso envisions a future where all chains operate as a unified system while maintaining their autonomy and speed. We aim to build a decentralized and sustainable network in collaboration with our community."