The BNB Chain, operated by leading crypto exchange Binance, has tested quantum-resistant cryptographic technologies on its blockchain. The trial revealed that achieving high security against quantum threats can lead to a striking drop in network speed, raising critical questions for the future of blockchain infrastructure.
Preparing for a quantum future
As one of the largest Ethereum-based blockchains by transaction volume, BNB Chain’s experiment provides valuable insights on how high-performance, mass-market blockchains might handle quantum security upgrades in the coming years. The findings highlight both the technical opportunities and bottlenecks involved in post-quantum transitions for the industry at large.
In this latest conceptual test, two core components at the foundation of BNB Chain — the ECDSA algorithm used for transaction signatures and the BLS12-381 scheme used by validators — were swapped out for post-quantum alternatives. This change caused the network’s transaction throughput to fall from 4,973 transfers per second to 2,997, a drop of around 40 percent. The increased size of quantum-resistant signatures significantly inflated the volume of data on the chain.
Key technologies and security practices
Most blockchains utilize ECDSA to let users prove wallet ownership by signing transactions with their private key. BLS12-381 is used among validators to confirm block validity and keep the chain updated. Both rely on elliptic curve cryptography. Experts warn that powerful enough quantum computers, leveraging tools like Shor’s algorithm, may someday break this protection.
During the test, the size of a single transaction ballooned from about 110 bytes to 2.5 kilobytes, while average block sizes surged from 130 KB to nearly 2 MB. The resulting slowdown was traced to data congestion created by these larger transfers, rather than by bottlenecks within validators themselves.
Alternative solutions across networks
Validator systems handling block confirmations and chain updates were less affected thanks to data compression. The real challenge stemmed from the oversized post-quantum digital signatures added to each payment, clogging network capacity.
BNB Chain is not alone in seeking quantum resilience. Bitcoin developers are working on long-term upgrades like BIP-360 that would natively integrate quantum safety features. Other researchers promote urgent, albeit costly, solutions that could operate within current rules.
On Ethereum, a more comprehensive and gradual approach is underway. The Ethereum Foundation has announced a post-quantum security initiative aiming to progressively upgrade wallets, validator infrastructure, and core network components. Instead of an abrupt shift, Ethereum is targeting a sustainable, phased adaptation.
TRON has opted to move quickly, with founder Justin Sun announcing the launch of a quantum-resistant testnet in Q2 2024, followed by a mainnet rollout in Q3. TRON’s fast-track strategy aims to spotlight the protocol as a quantum-secure leader among major blockchains.
The post-quantum era: new trade-offs ahead
The BNB Chain experiment signals a new phase of debate in the industry. The big question is no longer whether blockchains can be fortified against quantum attacks, but at what cost in speed and efficiency those defenses can be realized.
As BNB Chain’s technical report notes, quantum-resistant security mechanisms can introduce significant performance drawbacks on high-capacity blockchains, forcing the industry to grapple with complex trade-offs in the near term.
The post-quantum challenge is now front and center for blockchain developers and users. As quantum computing advances, balancing robust futureproofing with the demand for fast, cheap transfers will shape the sector’s next chapter.
