East Texas A&M Researchers Unveil Post-Quantum Lightning Design

Researchers at East Texas A&M University have developed a post-quantum design for Bitcoin's Lightning Network, called PQLN. This is the first implemented and experimentally evaluated system of its kind, protecting off-chain communication and payment functions without requiring changes to Bitcoin consensus.

PQLN uses ML-DSA digital signatures and ML-KEM key exchange alongside Lightning's existing cryptography, which has been standardized by the U.S. National Institute of Standards and Technology under FIPS 204 and FIPS 203.

The system addresses the existing Lightning quantum risk without attempting to replace Bitcoin's on-chain cryptography. PQLN distributes post-quantum node identities through BOLT 7 gossip, adds ML-KEM to the BOLT 8 transport handshake, signs BOLT 11 invoices with ML-DSA and adds post-quantum protections to BOLT 12 offers.

Testing found that post-quantum computation added relatively little processing time, with the slowest cryptographic operation measured by the researchers taking 0.33 milliseconds. Payments over an emulated 50-millisecond internet connection took an additional 19 to 53 milliseconds per hop, mostly due to transmitting larger post-quantum data.

The open-source implementation adds roughly 11,000 lines to a research fork of rust-lightning and is described as a research artifact rather than a production release. Additional interoperability testing against Core Lightning, LND, and Eclair is still required.