Researchers Build First Working Post-Quantum Defense for Bitcoin’s Lightning Network

In an announcement Tuesday, the team of researchers said that they built what they describe as the first full post-quantum security design for the Lightning Network.

As first uncovered in a research paper in September, the team said they added post-quantum cryptography to Lightning’s communications, payment requests and related systems, implemented in Rust-Lightning.

It works like this: The solution layers new quantum-resistant cryptography on top of Lightning’s existing cryptography rather than replacing it. It uses ML-DSA digital signatures and ML-KEM key exchange, post-quantum algorithms standardized by the U.S. National Institute of Standards and Technology, alongside the classical methods Lightning already relies on.

In this hybrid design, an attacker would have to break both the new and the old cryptography to compromise a connection or forge a payment request.

According to the team led by Dr. Ahmet Kurt, an assistant professor in East Texas A&M’s Department of Computer Science and Information Systems, it took about three to four months and roughly 11,000 lines of code — and it’s a complete working implementation, not just a small demo.

Lightning lets users make fast, cheap Bitcoin payments through a network of off-chain channels instead of recording each one on the blockchain.

Its cryptography could eventually be broken by powerful quantum computers, and that risk exists even if Bitcoin itself gets upgraded, because Lightning has its own communication and payment systems, the team said.

They added that their work demonstrates that Lightning’s off-chain systems can begin preparing for the quantum era independently while others focus on solutions for the mainnet.

Quantum researchers have warned that a time will come when Bitcoin’s software — which underpins the biggest and strongest computer network in the world — will need to be upgraded to deal with quantum computing.

While some crypto VC firms have urged action, top developers in the space have argued that many of today’s quantum computers have limited capabilities.

Still, they have noted that their development could arrive unexpectedly — just like advances with artificial intelligence — and have started developing some solutions, including top Bitcoin infrastructure firm, Blockstream.

This post Researchers Build First Working Post-Quantum Defense for Bitcoin’s Lightning Network first appeared on Bitcoin Magazine and is written by Mathew Di Salvo.