Bitcoin may require separate upgrades for Lightning Network quantum security

A research preprint published on Sept. 12 suggests that even if Bitcoin adopts post-quantum protections for on-chain transactions, the Lightning Network would require independent upgrades across five key areas. The study introduces PQLN, a hybrid post-quantum extension for the rust-lightning prototype, which incorporates ML-DSA and ML-KEM to secure gossip, peer connections, invoices, and onion packets. While the researchers demonstrated that post-quantum and classical nodes could coexist, the implementation significantly increased data overhead, with default configurations expanding gossip downloads by 10.2 times.