Fairgate Presents New Bitcoin Cryptography Research at Stanford
Fairgate's CTO Sergio Lerner and CSO Ariel Futoransky presented their latest research, "From Cut-and-Choose to Constant-Size Proofs of Garbling Correctness," at the Workshop on Cryptography for Bitcoin, co-located with the Science of Blockchain Conference 2026. The presentation introduced a succinct proof for garbled circuit correctness with constant verification cost and a STARK-recursive prover capable of processing 25k gates per second on commodity hardware.
Constant-size proofs of garbling correctness — Ariel Futoransky and Sergio Lerner (Fairgate Labs)
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Garbled circuits underpin a growing class of Bitcoin protocols — bridges, vaults, and covenant-like constructions — that express rich spending conditions without consensus changes. These rest on garbling correctness: a verifier must be convinced that a garbled circuit was produced honestly from an agreed Boolean circuit. The standard tool is cut-and-choose, in which the garbler commits to many circuit copies and opens a random subset; verifier communication and storage therefore grow as O(k·n) in the security parameter k and circuit size n.