zkDaily - 2026-03-13

零知识证明 zkDaily

ZKP Frontier Tracker 🎯

Fri

03.13

2026

ZK API Usage Credits: LLMs and Beyond

Blog

https://ethresear.ch/t/zk-api-usage-credits-llms-and-beyond/24104

Davide Crapis RLN

Davide Crapis and Vitalik Buterin discuss a ZK API usage credit protocol in their blog, addressing privacy, security, and efficiency in API metering, especially for LLM inference.

Notes

API metering struggles to balance privacy, security, and efficiency; Web2 auth and on-chain payments fall short.
Uses RLN for anonymous deposits and anti-abuse, preventing spam and double-spending.
Enables variable-cost APIs; users prove solvency and privacy via refund tickets and ZK proofs.
Dual staking enforces policy: servers can penalize but not profit, ensuring transparency.
Considers homomorphic encryption to optimize refunds and simplify client/ZK logic.

Collected by @icerdesign

零知识证明 zkDaily

Q&A Deep Dive 💬

Fri

03.13

2026

What problem does ZK API Usage Credits try to solve?

It aims to solve privacy issues in API metering. Today APIs usually require identity authentication or a payment for every request. This proposal lets users deposit funds once and make many anonymous API calls while the provider is still guaranteed payment.

What role does the Rate Limit Nullifier (RLN) play in the protocol?

RLN prevents users from reusing the same request allowance. If a user double spends a ticket, the protocol can recover the user’s secret key from two signals and trigger slashing. This enforces rate limits even for anonymous users.

What does the ZK proof guarantee in this protocol?

The ZK-STARK proves three things: the user identity commitment exists in a Merkle tree, refund tickets are valid and correctly summed, and the total potential spending does not exceed the deposit plus refunds. This ensures solvency while keeping the user anonymous.

Prompted by @icerdesign