BNB Reveals Biggest Challenge of Post-Quantum Network Migrations

The threat that quantum computers may eventually pose to blockchain security has been discussed for years by the cryptocurrency industry.

The majority of people believe that creating new cryptography that can withstand quantum attacks will be the most difficult aspect of getting ready for that future. But according to recent testing that BNB developers shared, the true issue might be much more practical: enormous increases in network data.

The tests showed that quantum-resistant cryptography performed fairly well. The network was still able to process and validate transactions without experiencing catastrophic slowdowns because verification speeds stayed reasonable.

The actual problem 

Conventional blockchain signatures are small. Currently, a typical transaction signature in BNB’s example requires about 65 bytes. Once quantum-resistant signatures were used, that amount increased to about 2.4 kilobytes.

Although it might not seem like much at first, the effect spreads throughout the entire blockchain.

The size of a typical transaction increased from about 110 bytes to about 2.5 KB. The total block size increased dramatically from about 110 KB to almost 2 MB as thousands of transactions were added.

The speed at which nodes can communicate with one another worldwide is immediately impacted by that increase.

Blocks and transactions are continuously shared between nodes on the blockchain. Data packets take longer to travel between regions as they get bigger. Because of the increased propagation delays, some validators receive updates later than others.

Even minor delays matter in blockchain environments that move quickly. Slower propagation raises the possibility of congestion, temporary chain splits, network inefficiencies, and reduced throughput.

Testing revealed a direct impact on performance as well. After quantum-resistant signatures were implemented, native transfer throughput decreased from 4,973 transactions per second to about 2,997 TPS.

Heavier network

This illustrates a developing reality for the cryptocurrency sector. There are other issues with post-quantum migration besides security. Scalability and infrastructure issues are also present.

Blockchains may require, in the future:

• higher capacity for bandwidth.
• improved compression mechanisms.
• more effective aggregation of signatures.
• or completely different network designs.

to manage quantum-resistant encryption on a large scale.

The industry still has time to get ready according to BNB’s findings, but the shift to post-quantum security will probably necessitate significant trade-offs between decentralization, speed, and security.