Bridger

This project enables safe, private, and trust-minimized asset transfers between Miden and Zcash by using HTLC-style P2IDE notes and a resolver to coordinate secret exchange. It solves the lack of native cross-chain interoperability between privacy networks, allowing users to swap or bridge funds without custodians, revealing identities, or risking loss. By guaranteeing atomicity, automatic refunds, and shielded transfers, it makes cross-chain swaps easier, safer, and fully privacy-preserving.

One major challenge was mapping traditional HTLC logic onto Miden’s P2IDE note model, which doesn’t behave exactly like hashlocks on other chains. Ensuring the secret digest, reclaim height, and consume window aligned correctly required several iterations, especially to prevent early consumption or unintended refunds. Another hurdle was coordinating Zcash shielded transactions with the resolver so deposits could be verified without leaking metadata. I resolved this by building a lightweight proof-of-payment check and refining the note creation flow until both chains could reliably complete the atomic cycle.