At the Bitcoin 2025 conference in Las Vegas, we sent bitcoin to Domo using Thunderbolt. Domo introduced BRC-20 and was one of Nubit’s early investors, backing us in December 2023. Nubit is the Bitcoin infrastructure company I co-founded; the demonstration brought together two questions we had been working on: how to verify activity built on Bitcoin, and how to make native bitcoin easier to transfer.
If you know Domo’s name, it is probably because of BRC-20, the token experiment he introduced in 2023. It lets people create and transfer interchangeable tokens on Bitcoin: units of a token, rather than one-of-a-kind collectibles. Instructions recorded on Bitcoin tell software how many tokens exist and who owns them.
That brought a new set of things to build around Bitcoin. Someone had to read those instructions, keep track of balances, and make the results trustworthy. These are questions about the correctness of the software interpreting the chain.
By the time of this payment, we had known each other for more than two years. Our conversations had moved from BRC-20 to native Bitcoin payments, and there was now something we could put in his hands.
In Wen et al. (2024), our collaborators and I proposed INDECURE, an execution layer for Bitcoin meta-protocols. A meta-protocol assigns additional meaning to records on Bitcoin, such as the token instructions in BRC-20. The work asks how a user can verify the resulting state instead of taking an indexer’s balances on trust. Domo is a coauthor of that work.
Thunderbolt is about moving bitcoin without requiring every payment to wait for a new transaction on the blockchain. One part of the design I like is that the sender and recipient can finish at different times. The recipient does not have to be there for a perfectly synchronized handoff. There is a lot of cryptography behind that, but the everyday action is familiar: send someone money and let them receive it.
The Thunderbolt paper (Wen et al., 2025) studies that transfer problem. BRC-20 and Thunderbolt address different objects: the first tracks tokens represented by Bitcoin inscriptions; the second moves control of bitcoin itself. A phone showing a successful payment is the visible outcome. The research is in making the meaning of that success precise.