Ethereum is working toward making its consensus, execution and data layers resistant to potential quantum computing attacks by December 2029. Researchers at a16z crypto have introduced a new system called Aerie to address challenges in this transition.
Ethereum currently relies on BLS signatures, which efficiently combine thousands of validator approvals. However, BLS signatures are not considered resistant to sufficiently powerful quantum computers. Replacing them presents a significant challenge because existing quantum resistant alternatives are substantially larger and more expensive to aggregate.
How Aerie works
Ethereum researchers have been developing leanVM, a system that uses cryptographic proofs to compress signatures and reduce the burden on validators. However, Justin Thaler, a researcher at a16z crypto, 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, with the advantage increasing 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.
Privacy considerations
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.
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.
Outstanding questions
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.
