TL;DR

• ZK technology is primarily applied for enhancing scalability, privacy, and credibility in various projects like Starkware, zkSync, Scroll, Mina, Risc0, Giza, EZKL.
• ZK technology requires significant computational power, leading to 10^4 to 10^6 computation overhead, posing challenges for infrastructure teams.
• The main approaches to generating ZK proofs are Proof Markets and Proof Networks. Proof Markets operate as open markets for trading ZK proofs, while Proof Networks have internal servers, offering a cloud service-like experience for generating proofs.
• The Proof Market approach allows for flexibility and cost-effectiveness, as it facilitates an open market for ZK proof trading without the need for high-end server management.
• The Proof Network approach provides a streamlined and developer-friendly experience, offering a hassle-free solution with less focus on market mechanisms, ideal for quick and reliable proof generation. Theoretically, it provides fast proof generation since order matching in proof market also takes time.
• Challenges include testing and debugging difficulties, new security concerns, potential vendor lock-in, higher costs for certain usage patterns and loss of token utility.
• Leading players are likely to be those with the most internal ZK proof demands, as they can leverage existing infrastructure and specialized teams, maximizing hardware utilization.
• Emerging applications include ZK Coprocessors, ZK Attestation, ZKML (Machine Learning), and ZK bridges, all contributing to an increased demand for ZK proof generation.
• Decentralized proof networks in the ZK space are driven by the blockchain industry's preference for security, censorship resistance, and privacy, although ZK's inherent security means decentralization is not a prerequisite for these benefits. Performance is the major concern for ZK.

Introduction

Growing ZK Demand

After years of research in ZK area, and vast improvement in performance, ZK is finally applied in real-world applications. Talented engineers apply ZK for

• Scalability
• Privacy
• Credible Compute

There are lots of interesting projects relying on ZK, like Starkware, zkSync, Scroll, Mina, Risc0, =nil;Foundation, EZKL, Giza, Polygon, Manta. These projects steadily and continuously generate ZK proof every day. The most popular ZK use case today is ZKRU to solve the Ethereum scalability problems. In the last month, ZK verification costs millions of dollars on Ethereum/Ethereum L2s.

https://dune.com/nebra/zkp-verify-spending A strong increase in ZK verification cost over last year.

This chart built by Near team illustrates the zkSN(T)ARK gas spending on Ethereum and L2s. It includes popular ZK projects like zkSync, Polygon, Aztec, Tornado Cash, Loopring, Worldcoin, Tailgun, Sismo, StarkNet, ImmutableX and dydx.

zkSnark takes 80% of the total costs on verification, compared to zkStark. Among all these projects, Worldcoin has the highest verification cost, followed by zkSync. Each worldcoin verification cost around $2. Each zkSync verification cost around $30.