Based on this video:https://x.com/therollupco/status/1836865139884151249

Two approaches within ZK space—ZKVMs and custom ZK-circuits—offer different paths for developers looking to implement ZKPs in their systems. This video discussion explores the key differences, benefits, trade-offs, and auditing challenges between these two approaches. We’ve discussed this topic before, and I’ve prepared the notes below, including those previous discussions.

ZKVMs

ZKVMs are designed to offer a general-purpose environment where developers can write applications using regular programming languages, such as Rust, and automatically integrate ZK proof generation without the need for cryptographic expertise. The flexibility and simplicity of ZKVMs make them appealing to a broad range of blockchain developers, especially those looking for rapid deployment and scalability.

Benefits of ZKVMs

  1. Ease of Development: ZKVMs allow developers to use standard programming languages, eliminating the need for specialized cryptographic knowledge.
  2. Faster Time-to-Market: By simplifying the development process, ZKVMs reduce the time and resources required to deploy applications.
  3. Scalability: ZKVMs can be optimized through techniques like GPU acceleration, making them suitable for applications requiring high throughput and scalability, such as rollups and cross-chain bridges.
  4. Broad Applicability: ZKVMs can be applied across a wide range of use cases, from DeFi to data privacy applications, making them a versatile choice for many projects.

Limitations of ZKVMs

  1. Generalization: While ZKVMs are efficient for general applications, they may not provide the same level of performance optimization as custom circuits in highly specialized tasks.
  2. Performance Ceiling: In some cases, particularly for extremely high-performance needs, ZKVMs may fall short compared to custom circuits tailored specifically for an application.

Custom Zero-Knowledge Circuits

On the other hand, custom ZK circuits offer highly optimized, case-specific solutions. These circuits are designed from the ground up to solve particular cryptographic challenges, allowing for better performance in certain specialized applications. However, custom circuits require deep cryptographic expertise and are resource-intensive to develop.

Benefits of Custom Circuits

  1. High Performance: Custom circuits can be optimized to provide the most efficient proof generation for specific tasks, surpassing ZKVMs in niche applications.
  2. Tailored Solutions: When performance and resource efficiency are paramount, custom circuits allow developers to fine-tune their cryptographic proofs to meet specific needs.

Limitations of Custom Circuits

  1. Complex Development Process: Custom circuits require highly skilled cryptographers and a significant investment in both time and resources to develop, making them less accessible for most projects.
  2. Slower Iteration and Scaling: Due to their specialized nature, custom circuits are not easily reusable, which can slow down development and scaling for large, multi-purpose projects.