[madars]

eCash is an answer to "can you move value privately?" (yes, with concessions). Radius is solving "can you execute a million conditional state transitions per second at sub-penny costs?" Blind signatures are still just value transfers and offer no expressivity. If your agent wants DvP with conditional logic, or trustless escrow that releases on programmatic conditions, Chaumian eCash doesn't help. LN gets you close to some forms of atomic exchange, but close-to-atomic isn't atomic, and neither gives you composability. You can move balances, but you can't orchestrate multi-step workflows that can't unwind in the middle.

[fruitworks]

I imagine you could have some contract that interacts with ecash, based on revelation of a blind signature. Similar to a HTLC.

I have actually written up some ideas for a system based on something like this that I called "chaumian coupons", but I would have to go through my notes to find it.

[madars]

Indeed, for any particular outcome you could design a custom protocol. In contrast, Radius gives you a generic execution environment. Going custom you lose EVM tooling, audited standard contracts, and every bespoke protocol needs its own security analysis, its own edge case handling, and its own integration work.

That said, the most important loss is composability: an agent can't take your Chaumian coupon escrow and snap it together with someone else's DvP protocol and a third party's rate-limiting wallet in a single atomic transaction. The power of a shared execution environment is that these interaction patterns don't need to be anticipated and designed around in advance. Agents aren't going to negotiate which custom protocol to use for every interaction (the necessary protocol might not even exist!), they will use shared infrastructure where composability of various primitives is the effortless default.