Today, May 5, the Ethereum Foundation (PSE) Privacy and Scalability team launched ACTA (Anonymous Credentials for Trustless Autonomous Agents), a privacy layer for artificial intelligence (AI) agents built on the ERC-8004 standard.
With the introduction of the ERC-8004 standard on the main network last January, Ethereum now allows AI agents to interact in an autonomous and verifiable manner. This is because the technology gives AI agents a portable identity and reputation that can be verified on-chain.
However, a limitation of ERC-8004 is that all Public and traceable agent interactions. In that context, a decentralized finance (DeFi) protocol operating through AI agents exposes its entire strategy to the indexers of those records, including which agents to work with, how often, and with what results.
According to a document shared by PSE, ACTA seeks to resolve this exposure using the following methods: Anonymous credentials based on zero-knowledge (ZK) encryption.
ZK allows agents to prove certain claims (such as exceeding a reputation threshold, authorized AI model origin, operating in a legitimate jurisdiction, or that there is a real human behind an action) without revealing the underlying data or interaction history.
Agent credentials under ACTA will not be published in any public record. According to the PSE document: stored off-chain And only a cryptographic fingerprint is recorded on Ethereum, proving that the credential exists and was validly issued, without revealing its contents. This allows agents to demonstrate verifiable properties without exposing any supporting data.
To prevent the same tests from being reused, ACTA uses a system of nullfire. A unique identifier is generated each time the agent sends a test to the protocol associated with that particular interaction. If the agent tries to present the same evidence in a different context, the system will reject it. Two nullifiers of the same agent for two different protocols are computationally independent, so no external observer can link them together.
The ecosystem of AI agents on Ethereum is expanding
ACTA comes at a time of accelerated growth in the standards upon which it is built. As CriptoNoticias explained, ERC-8004 was implemented on Ethereum on January 29th of this year, with around 15,000 AI agents registered. As of May 5, that number has exceeded 181,000. Approximately 1,107% growth in just over 3 monthsaccording to 8004-ScanScanner.
These agents work to automateTrading tasks, cryptocurrency operations, interaction with protocols such as Aave. Currently, the most reputable agent for the 8004-scan browser is Toppa, which offers mobile top-up, utility bill payments, and gift card purchases in over 170 countries, with payments processed using stablecoins.
As reported by CriptoNoticias, ERC-8004 is already running on the BNB chain, Polygon, Solana and other networks, so these agents are available on those chains.
In that context, ACTA does not replace ERC-8004, but builds on top of it, so agents already registered to this standard can adopt ACTA without changing their current infrastructure. Each protocol chooses a validation system that fits its requirements.
Finally, the proposal is in draft stage and PSE invites DeFi developers and ecosystem teams to participate in its review.
(Tag translation) Blockchain
