Vitalik: Privacy protection must span the entire stack; mixnets and encrypted payments are essential for AI agents.

Vitalik posted on X that encryption privacy is crucial to prevent the leakage of access patterns during API calls. Even when using local AI agents, external observers can still extract substantial user behavior information by analyzing search engine call logs. He argues that the first-layer solution is to route calls through a mixnet, but this introduces a need for DDoS resistance, which in turn leads to pay-per-call mechanisms—typically paid via credit cards or privacy-ignorant stablecoins—meaning true privacy protection ultimately depends on cryptographic techniques. Vitalik also emphasizes that privacy must be considered from a full-stack perspective, with the local AI agent layer being especially critical. He uses anti-aging research as an analogy: if 10 factors damage the body, fixing one extends lifespan by 11%, fixing two by 25%, and fixing three by 42%; similarly, data leak protection measures exhibit superadditive compound effects.