On June 5, Olaoluwa Osuntokun, lead developer of the Lightning LND client, posted a detailed technical analysis on the Delving Bitcoin forum about how quantum computing will impact the Lightning Network and what changes are needed to keep the protocol working.
According to Osuntokun’s post, the question is not whether Lightning should adapt; How to do it without dismantling the architecture. Analysis is based on accurate diagnosis. All layers of protocols based on classical security assumptions require changes.
Identify Osunto-kun Five protocol specifications known by the acronym BOLT (Foundation of Lightning Technology) Use Elliptic Curve Cryptography Directly:
- Invoice format to generate and read payment QR codes (BOLT 11/12).
- Encrypted transport between nodes (BOLT 8) for secure inter-node communication.
- Network discovery messages to find nodes and channels (BOLT 7)
- Onion Routing (BOLT 4), send payments privately
- Channel format for opening, closing, and updating channels (BOLT 2/3/5).
developer Each of these layers requires changes, butthe overall hierarchy of the protocol and its flow remains largely unchanged. In that sense, Osuntokun’s analysis is the first structured technical response to that exhibition.
Vulnerability is not theoretical. As CriptoNoticias reported last April, the Lightning Network’s public keys are permanently exposed to third parties, making them a direct attack vector. For a sufficiently powerful quantum computer.
One of the most important structural changes suggested by the analysis I lost my universal key. Currently, a single elliptic curve key is used to sign messages, establish encrypted connections, and authenticate nodes.
In a post-quantum scenario, it will likely be necessary to implement three different cryptographic systems to achieve current basic functionality: ML-KEM for transport, ML-DSA for off-chain signatures, and SLH-DSA for on-chain signatures.
Another major barrier is size. The key and Schnorr/ECDSA signature (currently used by Bitcoin) take up 97 bytes. This corresponds to 3,732 bytes for ML-DSA-44 and 7,888 bytes for SLH-DSA-128.
These differences have concrete consequences. Mr. Osuntokun said that the QR code currently used to send payment invoices; Able to encode post-quantum schemes within current limits.
The dilemma of hash-based schemes
A related finding of the analysis is the limitation of the scheme. Reduced SLH-DSA (SLH-DSA-128-24). This variant imposes a limit of 16 million signatures per key.
For a node with 1,000 channels that broadcast updates every 10 minutes, that limit would be exhausted within four months. Therefore, Osuntokun excludes SLH-DSA-128-24 as a candidate for the network discovery layer in favor of ML-DSA, which is a lattice-based scheme.
Will we move completely to post-quantum cryptography or? Maintain a mixed approach and lean analysis toward hybridization.
Hybrid post-quantum cryptography is a combination of classical and post-quantum schemes; if either is secure, the entire system is secure. This logic applies both ways. Post-quantum schemes may also prove vulnerable in the future.
Osuntokun proposes introducing new keys as optional fields in current messages and rejecting messages that do not contain them only in a later phase.
The analysis of Osunto-kun, according to the author himself, is as follows. The first concrete document written on the topic after receiving direct and indirect questions from the community. About the impact of quantum computing on lightning.
Our position as the primary maintainer of LND (the Lightning client with the highest usage share among network nodes) increases the technical and operational importance of our conclusions.
The underlying message of this analysis is that Lightning is not doomed by quantum threats, but that the adaptive process is key. Concurrent changes need to be coordinated With multiple layers of protocols. This is something that has historically taken years in the Bitcoin ecosystem and represents an unprecedented adjustment challenge in the Bitcoin ecosystem.
(Tag Translation)Bitcoin (BTC)
