In 12 tests, PQLN makes Bitcoin's Lightning Network communication levels resistant to quantum computers

A group of researchers from East Texas A&M University has published PQLN, the first system that makes the communication and routing levels of Bitcoin's Lightning Network resistant to quantum computers: a concrete and testable reality.

Summary

• Key points
• East Texas A&M launches PQLN to make Bitcoin's Lightning Network communication levels resistant to quantum computers
  • Lattice-based cryptography for quantum resistance
  • Code availability and open-source release
• PQLN protects critical functions of the Lightning Network with minimal impact on performance
  • Covered Lightning operations
  • Interoperability with legacy nodes and test results
  • Effects on performance and bandwidth
• The limits of PQLN and implications for Bitcoin's base layer security
• Community reaction and adoption prospects
• FAQ
  • What is PQLN and who developed it?
  • What functions of the Lightning Network does PQLN protect?
  • Does PQLN protect on-chain Bitcoin funds?
  • How does PQLN affect network performance?

Key points

• PQLN was published on September 12, 2026 by East Texas A&M University and adds post-quantum cryptography to the Lightning Network through the ML-DSA and ML-KEM algorithms.
• The code, nearly 11,000 lines added to a fork of rust-lightning, is public on GitHub.
• PQLN covers five critical areas: gossip, peer transport, invoice, payment onion, and offers.
• In the 12 test scenarios with mixed nodes, zero payments were blocked, with an overhead of 0.33 milliseconds or less per operation.
• The bandwidth for gossip increases by about 10 times with the default ML-DSA settings, reduced to about 4 times with the Falcon scheme.

East Texas A&M launches PQLN to make Bitcoin's Lightning Network communication levels resistant to quantum computers

PQLN, published on September 12, 2026, adds post-quantum cryptography to Bitcoin's Lightning Network without dismantling the existing infrastructure. Quantum computers are not yet capable of breaking Bitcoin, but the team at East Texas A&M, based at the RELLIS Campus, decided not to wait for the problem to become real.

The Lightning Network allows Bitcoin users to exchange payments off the main blockchain, without waiting for confirmation at the base level each time. This speed comes at a price: Lightning relies on the same elliptic curve cryptography, known as secp256k1, that protects Bitcoin itself. If a sufficiently powerful quantum computer were to break that math, both levels would remain exposed.

Lattice-based cryptography for quantum resistance

PQLN does not eliminate existing cryptography but complements it with algorithms based on mathematical lattices. The chosen tools are ML-DSA for digital signatures and ML-KEM for key exchange, both drawn from the family of algorithms that the National Institute of Standards and Technology has standardized specifically for this scenario.

Code availability and open-source release

The complete code, nearly 11,000 lines added to a fork of rust-lightning, is already online on GitHub. Co-author Ahmet Kurt and his colleagues designed the system so that updated nodes can communicate seamlessly with those that have not yet been updated.

PQLN protects critical functions of the Lightning Network with minimal impact on performance

The implementation covers five operational areas of the Lightning Network and keeps performance virtually intact, except for an increase in bandwidth dedicated to gossip.

Covered Lightning operations

PQLN protects gossip, peer transport, invoice, payment onion (the layer that ensures routing privacy), and offers, following the framework of the BOLT specifications.

Interoperability with legacy nodes and test results

I tests covered all 12 possible scenarios of combinations between updated nodes and legacy nodes. The result is clear: zero payments blocked in every single tested configuration.

Effects on Performance and Bandwidth

The additional cryptographic operations introduced by PQLN remain under 0.33 milliseconds per operation, an impact deemed manageable by researchers. The bandwidth chapter is more complex: gossip downloads increase by about 10 times with the default settings based on ML-DSA. Switching to the Falcon signature scheme reduces the increase to about 4 times.

The Limits of PQLN and the Consequences for Bitcoin's Base Layer Security

PQLN protects the communication and routing levels of Lightning, but does not cover the actual funds in the channels or any on-chain elements of Bitcoin. The reason is structural: changing the cryptography of Bitcoin's base layer requires a consensus upgrade, meaning the agreement of the entire network of miners and node operators on new rules.

This detail explains why the news matters beyond the technical aspect. A Lightning Network made resistant to quantum computers at its communication levels can protect payments and routing today, independently of the rest of the network, but leaves Bitcoin's economic core exposed until miners and nodes decide to move together. It serves as a reminder of how slow and complex any change to the base layer of the blockchain is, even when the defense technology already exists.

The Community's Reaction and Adoption Prospects

Discussions about PQLN appeared on forums like Delving Bitcoin and BitcoinTalk just days after publication, indicating immediate technical interest around the project. The open-source release, complete with a modified sample node, lowers the entry barrier for those wanting to study the approach or evaluate its adoption in other Lightning implementations.

It remains to be seen whether this initial attention will translate into broader integration. For now, PQLN offers the Bitcoin community a concrete and verifiable tool to begin testing the quantum resistance of the second layer, while the discussion on the base layer remains open.

FAQ

What is PQLN and who developed it?

PQLN, or Post-Quantum Lightning Network, is an implementation of quantum-resistant cryptography for Bitcoin's Lightning Network, developed by researchers at East Texas A&M University.

Which functions of the Lightning Network does PQLN protect?

PQLN protects five critical areas of the Lightning Network: gossip, peer transport, invoices, payment onions, and offers.

Does PQLN protect on-chain Bitcoin funds?

No, PQLN does not protect the actual funds in the channels nor the on-chain elements of Bitcoin, as a consensus upgrade on the base layer of the network would be required.

How does PQLN affect network performance?

PQLN adds a cryptographic overhead of about 0.33 milliseconds per operation and can increase bandwidth consumption for gossip by about 10 times with ML-DSA, or about 4 times using the Falcon signature scheme.

Content created with the assistance of artificial intelligence and human editorial review.