Ethereum’s proposed approach to quantum resistant security could introduce unnecessary complexity and conflict with its long term privacy ambitions, according to Justin Thaler, a researcher at a16z crypto.
In a Friday research announcement, Thaler and a team of cryptographers introduced Aerie, a system designed to aggregate thousands of quantum resistant digital signatures into a single cryptographic proof.
The researchers argue that lattice based cryptography offers significant performance advantages over the hash based systems being developed as part of Ethereum’s long term roadmap.
The announcement comes as Ethereum works toward making its consensus, execution and data layers resistant to potential quantum computing attacks by December 2029.
Aerie challenges Ethereum’s quantum security approach
Ethereum currently relies on BLS signatures, which allow thousands of validator approvals to be combined efficiently. However, the cryptographic system is not considered resistant to sufficiently powerful quantum computers.
Replacing these signatures presents a challenge because existing quantum resistant alternatives are substantially larger and more expensive to aggregate.
Ethereum researchers have been developing leanVM, a system that uses cryptographic proofs to compress signatures and reduce the burden on validators.
However, Thaler argues that the hash based approach requires multiple rounds of recursive proof aggregation, adding computational costs and complexity.
Aerie instead combines lattice based signatures with lattice based cryptographic proofs, allowing thousands of signatures to be aggregated directly.
In tests conducted on an Apple M4 Max laptop without GPU acceleration, Aerie aggregated 32,768 Falcon signatures in 0.65 seconds, equivalent to more than 50,000 signatures per second.
The resulting data averaged approximately 42 bytes per signature, while proof verification took 54 milliseconds on a single CPU core.
According to the researchers, Aerie processed consensus signatures 29 times faster than Ethereum’s leanVM in comparable benchmarks. The advantage increased to roughly 60 times for stateless transaction signatures.
The results are based on the researchers’ published benchmarks and do not establish how the system would perform across a live blockchain network.
Researchers question whether hash based systems can support private transactions
Beyond performance, Thaler raised concerns about the compatibility of Ethereum’s proposed cryptographic architecture with its privacy objectives.
The Ethereum Foundation’s draft roadmap identifies both quantum resistant security and native private transactions as long term priorities.
However, Thaler argues that relying exclusively on hash based cryptography cannot provide all the functionality required for private payments.
Private transfers require encryption so recipients can securely receive information about transactions, including when the sender and recipient have never communicated before.
Public key encryption cannot be constructed from hash functions alone in a general black box setting, according to established cryptographic research.
As a result, Thaler argues that Ethereum may eventually need structured cryptographic systems, such as lattices, regardless of whether it adopts them for signatures and proofs.
He also challenged concerns that future AI advances could compromise lattice cryptography, arguing that speculative attacks should be weighed against the complexity of existing alternatives.
Nevertheless, lattice based systems carry their own security and implementation challenges. The Aerie researchers acknowledge that Falcon signing has historically required complex arithmetic and substantial memory, although recent improvements have reduced those requirements.
Ethereum has not committed to adopting Aerie, and its proposed quantum resistant architecture remains under development.
The Ethereum Foundation currently aims to achieve full quantum resistance across the network by December 2029, with research continuing into signature aggregation, cryptographic security and private transactions.
Disclosure: This article was edited by Estefano Gomez. For more information on how we create and review content, see our Editorial Policy.