A Concurrent Merkle-Tree and Polynomial Commitment Framework for Off-Chain Bitcoin Transaction Batching

Abstract

Bitcoin's base-layer throughput is bounded by its block interval and block-size limits, which constrains the rate at which individual transactions can be confirmed on-chain. This paper presents Uni-Speed Bridge, an off-chain transactionbatching framework that aggregates a set of pending transactions into a single, fixed-size cryptographic anchor using two complementary constructions: (i) a Merkle tree, which preserves per-transaction data availability and enables O(log n) inclusion proofs, and (ii) a modular polynomial evaluation over a large prime field, which serves as an auxiliary batch-level commitment. The system is implemented in Go and uses a bounded workerpool concurrency model to parallelize transaction hashing across available CPU cores, together with a write-ahead log for crash durability and a retrying, idempotent JSON-RPC client for interaction with a Bitcoin Core node. We describe the architecture, provide a complexity analysis of each stage, and are explicit about what the system does not provide: it does not modify Bitcoin consensus rules, does not itself validate transaction signatures, and has not undergone independent security audit or empirical benchmarking on production hardware. We position this work as an engineering case study in off-chain data-availability design rather than a validated scaling proof, and outline the concrete steps-signature validation, zero-knowledge succinctness proofs, and third-party audit-required before any production deployment.