ZKP has the absolute advantage of low cost? Take Aztec as an example to discuss

By Kyle Liu, Investment Manager, Bing Ventures

Introduction: With the continuous development of ZKP (Zero-Knowledge Proof) technology, there is a strong interest in its relationship between cost and performance. Implementing and maintaining a Zero-Knowledge Proof system requires significant computing resources and algorithm optimization. These calculations can lead to high costs, especially when dealing with large-scale data and complex calculations. Therefore, the cost advantage of ZKP is not absolute, but depends on the specific application scenario.

Against the backdrop of the news that Aztec Connect was forced to shut down, we felt compelled to re-evaluate the claimed cost advantages of ZKP technology. Although ZKP is touted as a solution that offers a high degree of privacy, the temporary failure of Aztec Connect at least proves that the technology is a significant cost challenge at this stage.

If ZKP technology is really cost-effective, why can’t Aztec Connect be sustainable in its operations? More intriguingly, Aztec also encourages the community to fork, deploy and operate new versions of Aztec Connect. This implies the enormous resources required to run Aztec Connect independently. This further fuels our doubts about the cost-effectiveness of ZKP. If ZKP’s cost advantage is real, then why does the community need so much investment to keep this project running?

Therefore, we need to take a hard look at the claimed cost advantages of ZKP technology. Perhaps ZKP’s cost advantage is just an overblown illusion, but the reality may be more complex. In the pursuit of cost advantages, it is necessary to consider not only the optimization of individual aspects, but also the performance and cost balance of the overall system. For example, dropping computational costs may increase communication costs, or using more efficient algorithms may require more complex hardware support. Therefore, we need to conduct a comprehensive cost-benefit analysis for a specific project, weigh all aspects of the optimization strategy, and find the best balance.

Cost myths shattered

First of all, you need to define the cost structure of ZKP. At present, various definitions are complex and the standards are different, including at least hardware costs, computing costs, verification costs, storage costs, and other parts. However, from the author’s point of view, following the native principles of ZKP, our definition of cost structure in this article focuses on the two core costs of communication cost and computing cost. The communication cost refers to the cost of exchanging information between the prover and verifier, while the computational cost refers to the cost of performing the computation between the prover and the verifier. These two costs play a core role in ZKP, as they directly affect the efficiency and security of proof and verification. If the communication and computational costs are too high, the efficiency of proof and verification will be dropped, affecting the performance of the entire system.

Now returning to Aztec’s privacy architecture, we need to recognize that Aztec’s rollup approach is significantly different from other ZK-based Layer 2 solutions. Instead of aggregating multiple transactions to generate proofs, Aztec needs to generate proofs for each transaction separately and then package them. This approach results in the need to generate independent proofs for each transaction, which increases the computational cost and gas fees, making Aztec’s gas fees higher than other rollup schemes.

In addition, only the privacy proof generated locally by the user is a true Zero-Knowledge Proof that does not disclose information, and the internal and external rollup proofs on top of it are not necessarily zero-knowledge. This obscures the privacy benefits of ZKP and further calls into question the viability of ZKP’s cost benefits. Aztec Connect’s gateway approach is inherently bloated, aggregating transactions to Layer 1 and enabling fund aggregation and Defi function calls through Aztec Bridge Contracts. However, this gateway approach may only be applicable to certain types of transactions in terms of cost allocation, and it limits the flexibility of project deployment.

Cost-effectiveness that is difficult to measure

The relationship between cost and performance is complex and dynamic. Typically, a lower cost can improve performance because it reduces the overhead of computing and communication, which increases the efficiency of the overall system. However, too much pursuit of low cost can lead to performance degradation at the expense of computing and communication resources. As a result, the ZKP system needed to find the right balance between cost and performance to meet the needs of different application areas.

Zero-Knowledge Proof involves verifying the correctness of a claim between different actors through messaging, so communication costs are a key factor. To drop communication costs, efficient communication protocols and compressed Algorithm can be considered to reduce the size and transmission time of messages. Especially for Layer 2 projects like Aztec, Cross-Chain Interaction requires the transfer of messages and data between different Blockchain networks. Delivering messages involves network communication and interaction, which results in a certain communication cost. Especially for large-scale full-chain DApp construction, the amount of messages delivered will be larger, increasing the pressure on communication costs.

Zero-Knowledge Proof requires a lot of computation to generate proofs and verify the correctness of proofs. To drop compute costs, optimize Algorithm and data structures to reduce unnecessary compute steps and storage overhead. In addition, parallel computing and distributed computing technologies can be used to distribute computing tasks to multiple nodes to improve computing efficiency. ZKP is relatively inexpensive to verify on the target chain, but the process of generating proofs on the source chain is computationally expensive. Especially when using traditional methods for validation, the cost of verification is high and unaffordable for users.

More effective cost control strategies

The author believes that with the development of technology, the cost of communication may no longer be a major limiting factor. The continuous advancement of modern communication technology means that the cost of communication is declining on a large scale. Therefore, it may make more sense for us to focus more on the optimization of computational costs. However, as the application of such protocols expands, communication cost is likely to remain an important consideration, requiring continued attention to their specific scenarios for flexible use.

At the same time, we need to understand that the approach to optimizing computational costs is not limited to algorithm optimization. In addition to improving the Algorithm of the protocol, consider drop computing costs through technological innovations in areas such as specialized hardware, distributed computing, or Depth learning. These methods require more long-term research and empirical evidence, but they will definitely lead to breakthrough performance gains and cost advantages. We believe the following directions are more noteworthy in the future ZKP competition:

• High performance and low computing cost: A ZKP project with high performance and low computing cost will be in the spotlight. This means that the project is able to generate and verify proofs in an efficient manner while maintaining security and privacy. Such a project will have a wide range of application potential and be able to meet practical needs on a large scale. A variety of different ZKP attestation systems currently exist, each with its own unique advantages and limitations. We prefer projects that work to improve and innovate proof systems to increase efficiency, reduce computational costs, and enhance security. Developers need to explore more efficient Zero-Knowledge Proof constructs and more optimized Zero-Knowledge Proof verification Algorithms for faster and more reliable proof generation and verification processes.
• A successful ZKP project should be deployable in the real world. This means that it needs to take into account the constraints of the real-world environment and provide practical solutions. For example, considerations such as compatibility with existing infrastructure and systems, ease of integration and usability are important. The use of dedicated hardware to accelerate ZKP computing is an important research direction. Future research can focus on innovations in hardware acceleration technologies, such as the use of custom hardware such as FPGAs (Field Programmability Gate Arrays) or ASICs (Application Specific Integrated Circuits). With the help of hardware acceleration, the performance and efficiency of ZKP systems can be improved, providing better support for large-scale applications and real-time scenarios.

• Security Problem Solving: In the ZKP system, security is of paramount importance. Security issues in the ZKP system are the biggest hidden costs, such as the defense against attacks and vulnerabilities, the security of parameter settings, and the guarantee of randomness. Only by continuously improving the security of the ZKP system can such projects ensure its reliability and trustworthiness in real-world applications, providing users with a higher level of protection and privacy, which will continue throughout the cost and performance design process.

In summary, a promising ZKP project should have the characteristics of high performance and low computing cost, oriented to practical applications, secure and trustworthy, real-world deployable, and safe in the whole process. We can foresee that the continuous development of ZKP technology will provide a broader application prospect for privacy protection and verification performance. We also need to consider several factors when evaluating the cost-effectiveness of a ZKP project, including computing resources, security requirements, performance needs, and complexity of implementation and maintenance. In some cases, ZKP may provide significant privacy protection and security benefits, offsetting the increased cost. In other cases, however, the cost may exceed the actual value that can be provided.