Cloaking Layer — a ZK Verification Infra for All Chains

zCloak Network
10 min readMay 31, 2024


  • ZK proof verification is slow and expensive on Ethereum;
  • Cloaking Layer provides an alternative for fast and low-cost ZK proof verification;
  • It uses ICP canisters to run ZK verifiers which are compiled to WASM;
  • It uses threshold ECDSA signature to deliver the ZKP verification result to all chains;
  • Most existing ZK systems are supported;
  • Tons of new use cases can be unlocked using the ZK-as-a-Service model.

Rising Demand for Zero-Knowledge Proofs in Web3

The need for on-chain verification of Zero-Knowledge (ZK) proofs is growing quickly in the Web3 space. This is because ZK proofs improve privacy, security and scalability in decentralized applications. They allow verification of private data without revealing the data itself. This is important for applications like ZK payment systems, which keep transactions private and for ZK identity systems, which helps to preserve the privacy of user identity. As the Internet of Things (IoT) grows, ZK proofs also ensure secure data exchange between devices, addressing data privacy concerns in decentralized physical infrastructures (DePIN) in Web3. ZK proofs also help to validate the correctness of off-chain computations, ranging from zk-Rollups to zk-Coprocessors, greatly enhancing the scalability of blockchains.

Challenges of ZK Proof Verification on Public Blockchains

Despite the importance of ZK proofs in the Web3 world, integrating ZK proofs into public blockchains faces significant hurdles.

Bitcoin, primarily designed for secure peer-to-peer transactions, uses a simple scripting language that is not Turing complete. This simplicity limits its computational capabilities, making it unsuitable for handling the complex computations required for ZK proof verification. Therefore, Bitcoin cannot fully benefit from the privacy and scalability enhancements offered by ZK technology.

Ethereum, despite being more flexible and computationally powerful, also faces challenges with ZK proof verification due to the high cost involved. For instance, verifying simple SNARKs on Ethereum is about ten times more expensive than a standard ether transfer. The cost increases significantly with the size and complexity of the proofs, reaching up to 40–50 times higher for Plonk proofs and up to 1,000 times higher for STARK proofs. Additionally, Ethereum requires ZK proof verifiers to be written in Solidity, which complicates development and raises costs. These issues have slowed the introduction of new ZK applications and limited the variety of ZK algorithms available on the platform.

Other public blockchains face similar challenges. Many do not have the computational power or cost efficiency needed for ZK proof verification. Newer blockchains often optimize for specific purposes, like fast transactions or high throughput, and may not support the demanding computational requirements of ZK proofs. Even blockchains that are capable of such computations find the cost of verification prohibitively high, hindering widespread adoption.

Despite these challenges, integrating ZK proofs into blockchains is a critical area of ongoing research and development due to the significant potential benefits. Overcoming these obstacles will unlock the full potential of ZK technology and drive the next wave of Web3 innovation.

Cloaking Layer: Transforming ZK Verification

Cloaking Layer is an innovative ZK proof verification and interconnection infrastructure built on the Internet Computer (ICP). It aims to transform blockchain technology by providing ultra-fast, cost-effective, and highly secure ZK verification services across all blockchain networks. By enabling seamless interoperability and utilizing native threshold ECDSA/EdDSA signatures, Cloaking Layer ensures accurate and trustless delivery of ZK verification results. Committed to democratizing ZK technology for widespread accessibility, Cloaking Layer supports various blockchain applications, making advanced privacy and security features available to every developer and user in the ecosystem.

Cloaking Layer’s strategy of offering a universal verification layer by integrating existing ZK systems marks a strategic shift from developing proprietary ZK algorithms. This approach significantly accelerates the deployment and scalability of Web3 projects by removing the need for individualized proof system development. Instead, Cloaking Layer provides a “plug-and-play”-like solution compatible with a wide range of blockchain architectures, ensuring that applications can effortlessly verify ZK proofs regardless of the underlying technology. This universal verification layer benefits developers by reducing the complexity and technical barriers traditionally associated with implementing ZK proofs. By abstracting the intricacies of ZK technology into a more accessible service, Cloaking Layer enables even those with limited cryptographic knowledge to implement advanced ZK features in their applications. This is crucial for the widespread adoption of ZK technology, as it lowers the entry threshold for developers and companies looking to enhance their applications with state-of-the-art privacy features.

Moreover, this strategy enhances interoperability between different blockchain networks, a key advantage in an increasingly fragmented blockchain ecosystem. With Cloaking Layer, verification results can be seamlessly delivered across various blockchain networks without compatibility issues. This interoperability is pivotal for applications that operate across multiple blockchain environments, facilitating a more cohesive and integrated Web3 experience without compromising security or performance. Fundamentally, Cloaking Layer’s universal verification layer not only simplifies the development process but also expands the potential for ZK technology integration across the blockchain landscape, empowering developers to build more secure, private, and efficient applications.

Leveraging ICP for ZK Verification

Implementing ZK technology efficiently involves two steps: proof generation and proof verification. Cloaking Layer, a novel product from the zCloak Network, focuses on the latter step of proof verification by leveraging WebAssembly (WASM) within the versatile environment of Internet Computer (ICP) canisters. This setup ensures compatibility with various ZK systems, from well-established ones like Groth16 and Plonk to emerging technologies such as zkVM and zkEVM.

Cloaking Layer maximizes the capabilities of the Internet Computer’s architecture, particularly utilizing its chain key technology to deliver threshold ECDSA/EdDSA signatures. These signatures ensure precise and trustless communication of ZK verification results, facilitating transaction or data validation across different blockchains without any central authority, maintaining the decentralized ethos of blockchain technology. The incorporation of the threshold signatures enhances the platform’s utility, enabling interaction with almost any blockchain networks.

Cloaking Layer offers high security and interoperability at a low cost (several US cents per proof verification). This cost-efficiency is achieved through the native execution of WASM on high-performance computing nodes provided by the ICP, ensuring sub-second level verification finality. This rapid processing capability, combined with robust security measures, makes Cloaking Layer a technically innovative and economically viable solution for widespread adoption across various sectors.

System Architecture of Cloaking Layer

The system architecture of Cloaking Layer, illustrated in the provided diagram, showcases its integration within the Internet Computer (ICP) subnet to deliver ZK proof verification services. At the core of this setup is the Cloaking Layer Canister, a crucial component responsible for verifying both SNARK and STARK proofs. Various ZK systems are supported, including Polygon Miden, RISC0, Plonk, SP1, Jolt, etc. This flexibility is achieved by compiling these ZK systems into WebAssembly (WASM), ensuring compatibility and performance within the ICP environment.

The ICP Subnet comprises large number of replicas that execute the canister’s code simultaneously. When a ZK proof is submitted to the Cloaking Layer Canister, it is re-executed by each of these replicas. This decentralized processing model enhances the robustness and reliability of the verification process. Once the proof is verified, the verification result is signed by the replicas in the subnet using threshold ECDSA signatures. This cryptographic method ensures that the result is tamper-proof wherever it is used. Threshold signatures are particularly important for maintaining security and trust across the network, as they attest to the consensus formed by the majority replicas in the subnet.

The verified results then become available for other blockchain networks and applications. This includes integration with prominent platforms such as Bitcoin and its Layer 2 solutions, Ethereum and its Layer 2 solutions, as well as other blockchain networks like Solana, Sui, and Cosmos. Additionally, the verification results can be utilized by AI agents, enhancing their operations with secure and validated data. Fundamentally, Cloaking Layer’s architecture leverages the computational power and security features of the ICP to deliver a robust, scalable, and interoperable ZK proof verification service. This architecture not only simplifies the development process but also enhances the potential for ZK technology adoption, driving innovation and trust in the Web3 ecosystem.

Cloaking Layer V.S. Ethereum for ZK Proof Verification

Cloaking Layer and Ethereum differ significantly in their ZK proof verification capabilities and performance. Cloaking Layer offers an extremely low cost for verifying ZK proofs, ranging from several US cents, compared to Ethereum’s costs, which can escalate to tens, hundreds, or even thousands of USD. This cost advantage makes Cloaking Layer more economically viable for developers and users.

Cloaking Layer also boasts sub-second finality for proof verification, ensuring almost instant verification result confirmation. In contrast, Ethereum’s verification speed depends on block time, often resulting in delays, with aggregated proofs taking hours or even days, making it less suitable for applications needing immediate confirmation.

Interoperability is another strength of Cloaking Layer, which supports all blockchain networks, unlike Ethereum, where the verification result can only be used on one chain. This universal compatibility enhances Cloaking Layer’s flexibility, allowing for easy integration with various systems, while Ethereum’s limited composability can hinder complex applications. Another bonus is the reverse gas model of ICP — the gas fee for proof verification is paid by the infrastructure, not the users. This ensures seamless onboarding of everyone to the ZK world, without the need to hold and use any specific cryptocurrency.

Cloaking Layer also provides end-to-end unified trust without intermediaries by delivering the verification result via threshold ECDSA signatures under the same trust assumption. Whereas for Ethereum, different trust assumptions are introduced when the result needs to be bridged to other chains using a 3rd party bridge or oracle service.


Cloaking Layer provides ZK-as-a-Service for developers aiming to embed advanced ZK features into their applications. This service is particularly useful for projects within the Web3 ecosystem, spanning various sectors, including identity protocols, decentralized physical infrastructure (DePIN), AI agents, payments, zk-Machine Learning (zkML), and zk-Coprocessors. By offering an easy-to-integrate solution that handles complex privacy preservation tasks, Cloaking Layer enables developers to focus on the core functionality of their applications without needing to become experts in the underlying cryptographic technology.

The significance of ZK-as-a-Service lies in its ability to facilitate the immediate incorporation of privacy features into existing systems. For example, in identity protocols, ZK proofs can confirm the validity of a user’s credentials without revealing the actual data, thereby enhancing user privacy and security. In decentralized finance, ZK proofs ensure that transactions comply with regulatory requirements without disclosing sensitive financial information. This streamlines compliance processes and fortifies the trustworthiness of digital transactions on public ledgers.

Furthermore, deploying ZK-as-a-Service in sectors like AI and machine learning allows for the secure and confidential processing of data. Entities can leverage collective insights without exposing proprietary datasets or personal information, which is particularly relevant in industries where data sensitivity is paramount, such as healthcare or financial services. By integrating ZK proofs, organizations can collaborate and innovate while safeguarding their intellectual property and consumer data.

Typical use cases of Cloaking Layer’s ZK-as-a-Service model include:

  1. Identity: Enhancing user privacy and security by verifying identity of users, businesses or organizations, devices, and so on without revealing sensitive data.
  2. Payment: Ensuring compliance and security in financial transactions without disclosing sensitive information, while achieving a privacy-preserving payment systems.
  3. DePIN (Decentralized Physical Infrastructure): Protecting private user information while enabling secure data usage within physical devices, e.g. calculatng device scores without sending user data to a blockchain.
  4. Game: Providing privacy-preserving features in gaming applications, such as secret playing styles and strategies.
  5. Co-processor: Enabling the processing of off-chain data with validity proof posted on-chain to facilitate complex computation based on historical blockchain data.
  6. zk-Bridge: Providing secure and trustless interoperability of data and computations for bridges across different blockchain networks.

Ultimately, Cloaking Layer’s ZK-as-a-Service model simplifies integrating zero-knowledge proofs into diverse applications and democratizes access to cutting-edge privacy technology, making it accessible to anyone. This service is instrumental in fostering a secure, private, and trustworthy digital environment, which is critical as the Web3 space continues to evolve and expand.


Cloaking Layer is a pivotal innovation in the Web3 industry, significantly enhancing the usability and efficiency of ZK proofs. Developed on the Internet Computer (ICP), it aims to streamline and secure ZK proof verification across all blockchain networks. By addressing challenges like high costs, limited scalability, and complex integration, Cloaking Layer transforms ZK use cases in the Web3 ecosystem.

As a specialized infrastructure, Cloaking Layer offers unmatched efficiency and security, providing fast, cost-effective verification services. Its ability to enable interoperability among various blockchain ecosystems makes it essential for developers and enterprises using decentralized applications. Cloaking Layer also democratizes advanced cryptographic techniques, allowing developers without deep cryptographic knowledge to integrate privacy and security features. This accessibility fosters innovation and adoption in sectors requiring stringent data protection, such as finance, healthcare, and public services.

Ultimately, Cloaking Layer promotes a more secure, private, and efficient digital world. By solving ZK proof verification issues, it is poised to accelerate the evolution of Web3, enhancing blockchain scalability while prioritizing privacy and security. Cloaking Layer seeks to become a cornerstone technology for the next generation of blockchain applications, supporting a more interconnected and privacy-respecting digital future.

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