Vitalik Buterin Calls for Removal of Modexp Precompile Slowing Ethereum’s ZK Scaling

Buterin says modexp makes ZK-EVM computations up to 50 times heavier than average Ethereum blocks.

He proposes a new EIP to replace modexp with equivalent EVM code, despite higher gas costs.

Modexp’s inefficiency slows ZK-rollup progress, with few applications still requiring the legacy function.

Ethereum co-founder Vitalik Buterin has urged developers to remoVitaVve the network’s modular exponentiation precompile, known as modexp, describing it as one of the largest barriers to efficient zero-knowledge (ZK) scaling

In a recent X post, Buterin stated that the precompile is “by far the worst offender” for ZK-EVM prover efficiency, noting it can make computations up to 50 times heavier than average blocks. He suggested drafting a new Ethereum Improvement Proposal (EIP) to replace the function with equivalent EVM code, even if it demands higher gas fees.

Legacy Feature Creates Major Bottleneck

The modexp precompile, an early Ethereum component, handles modular exponentiation — a core operation in RSA encryption and digital signatures. While crucial in early cryptographic systems, the feature now hinders Ethereum’s evolution toward zero-knowledge technology

Buterin admitted that the code he originally designed has become a “burden” for modern scaling tools. According to his post, modexp’s inefficiency increases ZK proof generation costs and slows the development of technologies like ZK-rollups and ZK-EVMs

These tools depend on fast verification to process transactions off-chain and confirm them on Ethereum securely. Buterin also highlighted that modexp’s intricate code paths create potential consensus risks, complicating Ethereum’s long-term maintenance.

Low Usage Raises Questions on Necessity

Despite its complexity, only a handful of applications still rely on modexp. Buterin noted that most functions using it, such as RSA verification or bridge security checks, could transition to more advanced systems based on SNARKs — cryptographic proofs that efficiently handle ZK computations. He added that maintaining modexp’s optimization requires “heroic efforts,” which do not justify its continued use given its minimal adoption.

Instead, replacing modexp with standard EVM bytecode could simplify the ecosystem. While this change would increase gas costs for the few users who still depend on it, it would substantially reduce computational load and streamline ZK-proof generation for everyone else.

Broader Push Toward Efficient Cryptography

Buterin’s criticism fits into his broader campaign to modernize Ethereum’s cryptographic foundation. Last month, he detailed the GKR protocol, a verification method capable of processing two million calculations per second on standard hardware

This technique can validate complex Ethereum computations using fewer resources than traditional approaches. His recent proposals also emphasize creating clear benchmarks for measuring zero-knowledge and fully homomorphic encryption performance

Rather than prioritizing speed alone, Buterin advocates evaluating how much efficiency is lost when shifting to advanced cryptographic systems. This approach aligns with his ongoing effort to ensure Ethereum’s core remains efficient, scalable, and secure as the network advances deeper into ZK-based computation.

The post Vitalik Buterin Calls for Removal of Modexp Precompile Slowing Ethereum’s ZK Scaling appears on Crypto Front News. Visit our website to read more interesting articles about cryptocurrency, blockchain technology, and digital assets.