cross-chain offer safety using covered calls, a la "Trains, Hotels, and Async"

[dckc]

In YMax, I recently documented Offer Safety Limitations in the Orchestration SDK:

While support for Offer Safety in the Orchestration SDK is a goal with work-in-progress (#10504), currently, the use of basic orchestration features such as acct.localTransfer(seat, ...) moves assets out of the Zoe-managed seat before any want: might be satisfied.

We should be able to address this limitation using covered calls, as explained in Trains, Hotels, and Async - Agoric.

• proof of concept orchestration example contract
  • elaborate design / spec
  • turn it into an issue
  • delegate to a machine?
• durable version of covered call (essential?)

cc @erights @dtribble @toliaqat @michaelfig

[dckc]

@dtribble noted related work in the EVM world: Resource Locks - OneBalance Docs