1. Introduction
2. Polyhedra Network
3. Interoperability
4. zkBridge
5. zkDID
6. Applications on the zkBridge
7. Roadmap
8. Market Overview
9. Team
10. Conclusion

Introduction

In the rapidly changing landscape of digital technologies, the need for seamless connectivity between the Internet, blockchains, private networks, and the Metaverse is becoming increasingly apparent. However, the current multi-chain environment is characterized by isolated ecosystems, which cause liquidity and data fragmentation. While cutting-edge projects like zkRollup and zkEVM are primarily concerned with scalability, the critical aspect of interoperability in zero-knowledge technology is frequently overlooked.

Polyhedra Network emerges as a major player in the ZK space. It takes a comprehensive approach that addresses both ZK interoperability and scalability. The core of its offering is zkBridge, a ZK-based interoperability system designed and implemented by Polyhedra Network.

Polyhedra Network

Polyhedra Network is at the forefront of developing infrastructure to meet Web3’s needs for interoperability and scalability. It is ushering in a new era of dApps and blockchain networks by leveraging ZKP. Polyhedra Network’s core focus is on providing trust-minimised and highly efficient interoperability solutions across various Web 2.0 and Web3 systems. This includes facilitating seamless asset transfers, message passing, and data sharing between various decentralized platforms and traditional web applications.

Polyhedra Network’s innovative approach and use of ZKP technology aim to overcome the challenges of siloed ecosystems while improving the connectivity and functionality of the decentralized web. Polyhedra Network provides both interoperable and scalable solutions.

Interoperability 

As the Web3 ecosystem grows, the concept of interoperability becomes more important. Interoperability refers to the ability of multiple blockchains, protocols, and systems to communicate and collaborate seamlessly. Polyhedra Network envisions a future for Web3 that is fully interoperable, connecting various blockchains, Metaverses, and the larger Internet.

However, achieving interoperability presents significant challenges, particularly in securely connecting disparate blockchain networks. Cross-chain bridge protocols are critical for facilitating interoperability between different blockchain ecosystems. However, existing cross-chain solutions frequently rely on trust assumptions which makes them vulnerable to a variety of security threats. Attacks on cross-chain bridges have resulted in user losses totaling more than 2 billion USD. This highlights the critical need for strong and secure interoperability solutions that protect assets and ensure seamless cross-chain functionality of the ecosystem and its applications.

zkBridge

zkBridge connects disparate blockchain networks. This allows for seamless communication in the form of asset and data exchange. Furthermore, Polyhedra Network has created ZKP protocols that not only improve the interoperability of existing zkRollup systems but also enhance their efficiency. By leveraging its expertise in both ZK interoperability and scalability, Polyhedra Network hopes to reduce fragmentation in the multi-chain ecosystem.

By using zkSNARKs, zkBridge enables one blockchain (sender chain) to convince another blockchain (receiver chain) that a particular state change has taken place. It consists of two main components: a block header relay network and an updater contract. Block headers are fetched from the sender chain by the block header relay network, which also creates proofs of the headers’ validity before sending the proofs and headers to the updater contract, which runs on the receiver chain. The updater contract keeps a condensed picture of the state of the sender chain. It automatically updates its view of the sender chain by incorporating verified block headers.  

The zkBridge solution uses three powerful zero-knowledge proof (ZKP) algorithms, Libra, Virgo, and deVirgo, to enable secure and efficient communication between blockchain networks. These algorithms allow zkBridge to achieve seamless cross-chain interoperability to achieve both security and efficiency.

Libra is an advanced ZKP system that allows for rapid proof generation and verification without disclosing sensitive information. It introduces a linear time sum check protocol for general circuits which significantly improves efficiency over previous approaches. 

Virgo builds on Libra’s foundations by removing the need for a universal trusted setup and providing optimizations for custom gates. It excels at scalability and efficiency, with quick proving times, small proof sizes, and low verification complexity.

deVirgo is derived from Libra and Virgo. It improves distributed proof systems by incorporating distributed sum checks and distributed polynomial commitment techniques. This design allows for optimal parallelism, significantly reducing proof generation time by leveraging a distributed computing network. By minimizing communication during the main computation phase, deVirgo achieves remarkable speed that allows zkBridge to run up to 100 times faster than a single-thread Virgo prover. Key features of deVirgo include optimal parallelism, improved performance over single-thread Virgo, and the ability to use recursive composition to reduce the proof size and verifier cost for on-chain verification. Overall, deVirgo is critical to zkBridge’s efficient cross-chain communication to provide unparalleled performance and scalability.

zkDID

Polyhedra Network understands the importance of ensuring that the future of Web3 remains interoperable with the broader Internet, which serves billions of users. To accomplish this, they created zkDID, a scalable and interoperable decentralized identity (DID) solution based on Soul-Bound Tokens (SBTs) and verifiable credentials that utilize zero-knowledge proofs.

The primary goal of zkDID is to support millions of verifiable credentials per second, allowing billions of users to access Web3 infrastructures and applications easily.  Polyhedra Network uses SBTs, or Non-Fungible Tokens (NFTs), as scalable data containers. These smart NFT containers connect various credential issuers and both Web2 and Web3 applications. The zkDID infrastructure follows W3C standards and supports a wide range of verifiable credential data types, ensuring cross-system compatibility. By leveraging zkBridge for data interoperability, zkDID allows for seamless communication between relevant parties in a Web3 DID system, improving overall interoperability across Web3 and Web2 ecosystems.

In essence, zkDID is a significant step forward in decentralized identity solutions, providing scalability, interoperability, and compatibility with existing standards, simplifying communication, and facilitating widespread adoption of Web3 technologies.

Applications on the zkBridge

Bitcoin Messaging Protocol

The implementation of zkBridge for Bitcoin is a groundbreaking step toward improving interoperability within the Bitcoin ecosystem. Bitcoin can function as both a sender and receiver chain thanks to zkBridge, which provides comprehensive security via zero-knowledge proofs for consensus and transaction validation.

In the sender chain direction, zkBridge allows the receiver chain’s updater contract to directly verify Bitcoin’s consensus and transaction data via Merkle proofs. This compatibility ensures that all current and historical Bitcoin data can be accessed by layer-1 and layer-2 networks. This allows for seamless interaction with other blockchain networks and applications.

However, leveraging Bitcoin as a receiver chain is difficult due to its lack of native smart contract functionality. To address this, a Proof of Stake mechanism is used, in which validators stake native tokens (such as Ethereum or BNB tokens) to write data to the Bitcoin network. A Multi-Party Computation (MPC) protocol is used to achieve consensus on cross-chain transactions, which increases protocol robustness.

Importantly, the security of this protocol is not entirely dependent on the accuracy of the MPC protocol. In the event of malicious activity within the MPC committee, users can submit a zkBridge request to validate and potentially remove the malicious message. This decentralized and economically motivated approach ensures the security of user assets and provides recourse in the event of protocol manipulation.

ZKP Cross-Chain Messaging

Polyhedra Network’s team designed and developed Polyhedra zkLightClient technology, a ground-breaking solution based on the LayerZero protocol. This innovative technology enables secure and efficient cross-chain infrastructure, meeting both Layer-1 and Layer-2 interoperability requirements within the Web3 ecosystem.

LayerZero is an omnichain interoperability protocol that enables seamless cross-chain messaging for blockchain applications across 50+ supported blockchains. Polyhedra Network, on the other hand, pioneers Web3 interoperability by utilizing cutting-edge zero-knowledge proof (ZKP) technology. Their Polyhedra zkLightClient, which is integrated with LayerZero’s messaging protocol, allows developers to use ZKP and make cross-chain application development easier.

LayerZero’s ULNv2 validation library enables message transfer between on-chain endpoints. However, on-chain transaction verification, particularly with Ethereum, incurs significant costs due to large transaction logs. Polyhedra’s zkLightClient technology, which is based on LayerZero, optimizes on-chain verification using ZKP compression, significantly lowering costs and latency. Several transaction verifications can be combined into a single zero-knowledge proof which increases efficiency and scalability. 

Roadmap

At Polyhedra Network, the team is committed to transforming the digital landscape by unlocking exponential improvements to computational power and cross-platform interoperability within the vast blockchain ecosystem and the intersecting domains of Web2 and Web3. In the first stage, central to their mission is the innovative zkBridge, Polyhedra’s flagship technology, designed to overcome the critical challenges of interoperability, facilitating trustless, efficient, and secure transactions across a variety of blockchain networks. More importantly, zkBridge provides a perfect environment to develop, test, and strengthen our proof system, which is the foundation of our vision. Polyhedra further expands the zkBridge protocol to a general ZK interoperability protocol, which also empowers interoperability between Web2 and Web3 applications, and helps to onboard real-world assets (RWAs) to Web3.

This grand vision is underpinned by Polyhedra’s innovative protocols and cutting-edge algorithms, forming a robust computation foundation that supports the entire blockchain ecosystem. Polyhedra enables developers to harness a variety of data and computational resources to build diverse protocols and applications within a limitless environment driving technological progress at an unprecedented scale. Through these layers of technological innovation, Polyhedra strives to build a more connected, efficient, and secure digital future, driving the evolution of blockchain technology and creating new pathways for data exchange and collaboration between traditional and decentralized networks. 

Market Overview

The market for blockchain interoperability, which allows for seamless asset transfers across different blockchain networks, increased significantly in 2022, reaching USD 275.5 million. This expansion is expected to continue, with a projected Compound Annual Growth Rate (CAGR) of 26.8% from 2023 to 2032. This increase can be attributed to the growing demand among users and businesses to transfer assets and data across various blockchain platforms. Interoperability solutions play an important role in facilitating secure and efficient cross-chain asset transfers, which improves the functionality of various blockchain networks.

Interoperability in blockchain technology enables dApps to leverage the distinct capabilities of various blockchain platforms which results in more versatile and powerful apps. However, despite its benefits, interoperability raises concerns about regulatory compliance across jurisdictions. Because blockchain technology is subject to varying levels of regulatory oversight worldwide, navigating these regulations can be difficult when implementing cross-border data sharing, ensuring legal compliance, and protecting data security. 

The COVID-19 pandemic had both positive and negative consequences for the blockchain interoperability market. On the one hand, the crisis highlighted the importance of secure and transparent data sharing, resulting in increased interest in blockchain solutions. Issues such as supply chain disruptions highlighted the importance of interoperability in improving transparency and traceability. However, the pandemic posed challenges for collaborative efforts due to remote work restrictions, and resources were redirected away from blockchain development. Despite these challenges, the pandemic demonstrated the potential for blockchain interoperability.

Looking ahead, the blockchain interoperability industry is expected to grow significantly as blockchain technology becomes more widely adopted. Enterprises looking into blockchain solutions may need interoperability to connect private or consortium blockchains with public blockchains or other industry-specific networks. 

Polyhedra Network envisions itself as a comprehensive full-stack zk project that addresses both zk interoperability and zk scalability, using tools such as zkBridge and zkDID to bridge the gap between Web2 and Web3. At the infrastructure level, Polyhedra Network uses advanced zero-knowledge proof protocols within zkBridge to connect any two blockchain networks. Moving beyond infrastructure, Polyhedra Network integrates zkDID into middleware and application layers, leveraging interoperability technologies to improve connectivity between Web2 and Web3. 

Team

Polyhedra Network team members graduated from renowned universities, such as UC Berkeley, Stanford University, Tsinghua University, SJTU, MIT, and Princeton University. The engineering team specializes in cryptography and zero-knowledge proofs and has experience in deploying large-scale blockchain and ZKP systems. Polyhedra Network is backed by top VCs such as Polychain Capital, Binance Labs, OKX Ventures, Animoca Brands, dao5, Mapleblock Capital,  and Hashkey Capital.

Conclusion

Polyhedra Network is pioneering the next wave of Web3 interoperability by leveraging advanced zero-knowledge proof protocols. Central to their efforts is the development and implementation of the zkBridge protocol, which is a trustless and efficient solution for facilitating cross-chain interactions between Layer-1 and Layer-2 blockchains. zkBridge uses zero-knowledge proofs to ensure robust security measures without requiring external assumptions or additional trusted parties, thereby increasing the overall trustworthiness of cross-chain transactions. Moreover, zkBridge significantly reduces on-chain verification costs, making the interoperability process more cost-effective and scalable.

In essence, Polyhedra Network’s zkBridge protocol represents a significant advance in Web3 interoperability, providing a dependable and efficient means for seamlessly connecting disparate blockchain networks while maintaining high levels of security and reducing overhead costs. Polyhedra Network aims to embody versatility and strength as a full-stack zk solution, enabling seamless interoperability and scalability across diverse blockchain ecosystems. Polyhedra Network’s comprehensive approach aims to play a pivotal role in shaping the future of decentralized technologies.