Garbled Circuits and BitVM3
The BitVM Alliance is pivoting to garbled circuits, as they make SNARK verification on Bitcoin over 1000x more efficient than BitVM2, enabling drastically cheaper BTC bridges. A vast design space is now being explored in parallel by multiple teams.
One such approach is BitVM3, which strikes a practical balance between implementation complexity, communication overhead, and proving cost.
The design is inspired by Jeremy Rubin’s Delbrag scheme. The key improvement is that BitVM3 circuits can be verified in plaintext and then reblinded — addressing Delbrag’s main drawback: the need for either expensive circuit correctness proofs or 200kB disprove scripts.