Project Introduction
Introduction:
Espresso Systems started out wanting to build a highly scalable, privacy-focused decentralized L1 protocol, but later found that not so many L1s were needed, so it will realize its mission by building for the Ethereum ecosystem. To achieve this vision, two separate efforts were taken to solve privacy and performance issues respectively.
To provide better privacy options, Espresso developed CAPE applications, which is Espresso's smart contract system that can achieve custom configuration of transaction-level privacy. CAPE can be deployed on any EVM chain.
A sorter is responsible for validating and batching transactions made on the layer 2 blockchain, which are then sent back to the layer 1 chain (like Ethereum) for settlement. Rollups don’t actually require a sorter; it’s just a design choice to give users a better experience with lower fees and faster transaction confirmations.
The main issue with sequencers currently is that they tend to be prone to centralization (in many cases being run by a single operator) and present risks such as transaction censorship, MEV extraction, and creating single points of failure (i.e. validity issues).
Solutions like Espresso’s shared sorter, which relies on separate, permissionless network nodes, are designed to help solve this problem. Espresso is creating a marketplace for shared sorting, through which layer 2 chains sell block space to shared proposers, including proposers on the Ethereum mainnet EVM itself, who create surplus value by satisfying user intent on multiple chains.
Technical architecture
CAPE
CAPE is an implementation of Espresso Systems' Configurable Asset Privacy protocol on Ethereum. Configurable Asset Privacy is a protocol that enables asset creators to issue private digital assets while specifying parties that can view specified data about ownership and transactions. CAPE also supports more advanced strategies using private verifiable credentials, freezing keys, or threshold schemes.
VERI-ZEXE — Decentralized Private Computing (DPC) System
In 2019, Bowe et al. proposed a scheme called decentralized private computation (DPC), which allows users to perform arbitrary computations off-chain and submit transactions using zero-knowledge proofs to prove the correctness of the computation. They implemented a system called ZEXE (zk-execution), which instantiates the DPC scheme to address the two pain points mentioned above. Roughly speaking, ZEXE is a "programmable Zcash" that generalizes from a single application system to a smart contract system while retaining privacy guarantees.
VERI-ZEXE improves the state-of-the-art by ~9.0x in transaction generation and ~2.6x in memory usage, and is used in future versions of CAPE to enable arbitrary user-defined asset strategies while maintaining configurable asset privacy.
HotShot
HotShot is a consensus protocol that prioritizes high throughput and fast finalization, and is based on the HotStuff protocol.
HotShot is open and permissionless, and it decentralizes participation in the sorter network, while providing high throughput and fast final results, while also ensuring security and effectiveness. HotShot uses a proof-of-stake ("PoS") security model, and one of the key requirements put forward by the Espresso team is to achieve strong performance without affecting the size of the validator set. Specifically, HotShot should at least be able to expand to include participation from all Ethereum validators (currently over 700,000).
Tiramisu
Tiramisu is a data availability solution that is innovative in that it has three novel layers; most rollups rely on L1 blockchains (such as Ethereum) to provide data, but the disadvantage is that it is very expensive.
Tiramisu's base layer is called Savoiardi. It is a bribe-resistant layer (similar to Ethereum's danksharding proposal) that provides the highest level of security. However, due to this feature, it is the least user-friendly of the three layers. To address this, Espresso added two more layers to its solution.
Mascarpone is the middle layer that ensures efficient data recovery by electing a small data management committee.
Cocoa is aptly named the "top sprinkler" of the entire system. Cocoa helps Tiramisu deliver "Web2-grade performance" by providing a content delivery network for Tiramisu. This helps with efficient data recovery and greatly speeds up data propagation. Given that this layer is centralized in nature, it is completely optional and Tiramisu works perfectly without it. It helps speed up data availability and can be easily changed or removed.
Espresso Systems designed its protocol with flexibility and modularity in mind, and rollup devices using its sequencer can also use any other data availability solution if they do not want to use Tiramisu.
EspressoSequencer
It is a decentralized transaction ordering system for layer 2 scaling solutions on Ethereum, a decentralized shared ordering layer
Espresso Sequencer is designed around a single decentralized proof-of-stake security model that supports a consensus protocol for ordering transactions and a data availability mechanism that enables further performance benefits. It also includes a rollup contract system that registers committed blocks of ordered transactions, verifies their consistency with the consensus protocol and availability certificates, registers updated state commitments for each zk-VM deployed to the Espresso Sequencer, and receives and verifies proofs of state updates.
Espresso Sequencer enables decentralization of L2. It handles decentralized ordering of rollup transactions and data availability, acting as a middleware between rollups and their underlying L1 platform. Espresso Sequencer is designed as a platform on which any zk-VM or optimistic VM can be deployed. Eventually, Espresso can also act as an interoperability layer by replicating zk-VM and optimistic VM to multiple L1s simultaneously.
Development process
2022/06/15 —- Espresso starts using CAPE on the Goerli testnet
2022/11/28 —- Espresso releases Espresso Testnet 1---Americano, the first public release of Espresso Sequencer
2023/07/20 —- Espresso Systems and Polygon zkEVM launch shared Doppio testnet
2023/08/05 —- Espresso opens the Doppio testnet to the public and releases a demo of the end-to-end integration of the Espresso Sequencer with the Polygon zkEVM stack.
2023/09/29 —- Espresso Systems releases testnet 3---Cortado, seamlessly integrating OP Stack aggregation and Polygon zkEVM aggregation to achieve decentralized, shared ordering.
2024/01/26 —- Espresso Systems releases Testnet 4, Gibraltar, showcasing integration with the Arbitrum technology stack. And for the first time, see external operators running Espresso Sequencer nodes.
(This testnet release also sees Espresso Sequencer support for four rollup stacks (Arbitrum, Cartesi, Optimism, and Polygon zkEVM) and multiple collaborations with Rollup projects.)
2024/02/03 —- Espresso is about to launch its fifth testnet, Cappuccino, where more entities will be recruited to run Espresso Sequencer nodes to further decentralize the sequencer. It is planned to be released at the end of the first quarter of 2024.
2024/03/13 —- Espresso is creating a shared ordering market through which layer 2 chains sell block space to shared proposers, including proposers on the Ethereum mainnet EVM itself, who create surplus value by satisfying user intent on multiple chains.
2024/05/22 —- Espresso releases testnet 5---Cappuccino, Espresso has expanded the HotShot final layer to 100 nodes on the Cappuccino testnet. The testnet also adds support for Arbitrum fraud proofs.
ecosystem
Project Cooperation
2023/07/19 —-Espresso Systems and EigenLayer announced an ecosystem partnership to leverage re-collateralization on the Espresso Sequencer network. Through EigenLayer, Espresso Sequencer will be able to access Ethereum’s staking capital base and decentralized validator set, thereby optimizing node usage and improving capital efficiency.
2023/07/20 —- Espresso Systems and Injective are collaborating, with Injective integrating the Espresso Sequencer, starting with Cascade, the first interchain Solana SVM rollup for the IBC ecosystem and demonstrating Injective’s commitment to long-term decentralization and scalability. Cascade is currently in public testnet, allowing developers to deploy Solana contracts on Injective and the broader IBC ecosystem for the first time.
2023/07/20 —- Espresso Systems and AltLayer will bring Espresso Sequencer to the AltLayer Stack, providing developers with more options for accelerating decentralization through AltLayer's decentralized verification and Espresso Sequencer. The two companies will explore integrations between Rollups built using the AltLayer platform and Espresso Sequencer.
2023/07/20 —- Espresso Systems and Catalyst collaborate to improve interoperability, with Catalyst becoming the first application dedicated to the Espresso Sequencer ecosystem. Catalyst is a cross-chain AMM platform focused on connecting modular blockchains. Catalyst is committed to leveraging the Espresso Sequencer, laying the foundation for secure and seamless cross-rollup interoperability. In the coming months, Catalyst plans to prioritize the deployment of Rollups using the Espresso Sequencer.
2023/07/20 —- Espresso Systems announced plans to integrate with Spire, a layer 3 aggregation-as-a-service offering, publicly announcing plans to use the Espresso Sequencer for sequencing and data availability.
2023/07/20 —- Espresso Systems launches a testnet integrated with the Polygon zkEVM stack, which allows users to submit transactions to a branch of the Polygon zkEVM, which are then routed to and sorted by nodes running the Espresso HotShot protocol.
2023/07/20 —- Espresso Systems and Caldera bring decentralized sequencing to the OP Stack. Espresso Systems and Caldera will deploy optimistic rollup, using Espresso Sequencer for ordering and fast confirmation, and Espresso Data Availability (DA) for storage. Caldera will provide the OP Rollup interface, site hosting, block explorer, and indexer.
2023/12/21 —- Espresso Systems and Offchain Labs announced a collaboration to bring decentralized versions of Timeboost transaction ordering and the Espresso Sequencer to the Arbitrum ecosystem and beyond. Timeboost is a transaction ordering strategy originally developed by Offchain Labs that is designed to protect users from front-running and mitigate the harmful effects of Maximum Extractable Value (MEV).
2024/01/26 —- Espresso Systems has partnered with blockchain infrastructure provider Blockdaemon, which will support Espresso Systems by deploying external sequencer nodes. It will manage 4 sequencing nodes located in Europe and Asia.
Currently cooperating
2024/03/08 —- Espresso Systems and Across have partnered to enable Across Protocol to leverage Espresso’s fast pre-confirmation capabilities secured by the HotShot consensus protocol, which reaches finality after two consecutive blocks. The integration will leverage HotShot’s shared security and fast finality to bridge between Rollups.
project team
Ben Fisch, CEO and co-founder of Espresso Systems, is an assistant professor of computer science at Yale University and previously a doctoral student at Stanford University, working with Dan Boneh in the Applied Cryptography Research Group.
Charles Lu — CEO and co-founder of Espresso Systems. Previously, he served as the head of Binance Labs at Binance. Charles Lu studied at Stanford University.
Benedikt Bünz — Co-founder and Chief Scientist at Espresso Systems. PhD student in Dan Boneh’s Applied Cryptography Group at Stanford University. Focuses on cryptography for cryptocurrencies.
project financing
Espresso raises $60 million in seed and Series B funding
On March 6, 2022, Espresso Systems has raised $32 million in funding, led by Greylock Partners and Electric Capital, with participation from Sequoia Capital, Blockchain Capital, and Slow Ventures. Espresso Systems also includes major industry players as backers, including Polychain Capital, Alameda Research, Coinbase Ventures, Gemini Frontier Fund, Paxos, and Terraform Labs.
On March 21, 2024, Espresso Systems announced that it had completed a $28 million Series B financing led by A16zcrypto. Espresso pointed out that Polygon, Taiko, o1Labs, StarkWare, Offchain Labs, and strategic investors from more than 30 ecosystem projects joined their recent Series B financing.
Project Summary
As an integral component of blockchain networks, transaction ordering has become a growing problem in the Layer 2 (L2) space. The solution is a shared, decentralized orderer. A shared orderer essentially provides a decentralized service for rollups. In addition to solving issues such as censorship, MEV extraction, and validity, a shared orderer introduces cross-rollup functionality, opening up a variety of new possibilities.
As a middleware, Espresso mainly provides shared sorting services. Through a shared sorting market and powerful finality tools, it brings new unity and efficiency to the Rollup and Ethereum ecosystem. Through fair economic incentives and sorting income distribution, Espresso not only solves the current Rollup fragmentation problem, but also lays the foundation for future cross-chain operations and a wider ecosystem. In short, keep paying attention.
Related Links:
Official website: https://www.espressosys.com/
Medium：https://medium.com/@espressosys
Twitter：https://twitter.com/EspressoSys
Docs：https://docs.espressosys.com/sequencer
Hackmd：https://hackmd.io/@EspressoSystems
Espresso testnet browser: https://be.cappuccino.testnet.espresso.network/
Related article: Espresso-based: Temporal shared ordering of all L2s, from aggregation-based to verification-based
Related article: Binance Research: A Deep Dive into Decentralized Sorters
