Cardano activates Van Rossem upgrade after on-chain vote

Cardano has activated the Van Rossem hard fork, moving the blockchain to protocol version 11 and adding changes aimed at making smart contracts cheaper to run. For ADA holders and app users, the bigger signal is governance: Decrypt reported that this was Cardano’s first major upgrade approved fully through on-chain community voting rather than directed by Input Output, the network’s founding development company.

Intersect, a Cardano member-based organization, said on X that the Van Rossem hard fork had been enacted on Cardano mainnet. Decrypt reported that the upgrade went live July 18 with zero downtime.

A hard fork is a required change to a blockchain’s core rules. Because every node, or computer running the network software, has to follow the same rules, hard forks are closely watched by users, developers and token holders.

How the vote cleared

The Van Rossem upgrade was approved by three parts of Cardano’s governance system, according to Decrypt.

Delegated representatives, known as DReps, supported the proposal with 77.63% approval, above the required 60% threshold. DReps are community members elected to vote on behalf of Cardano holders.

Stake pool operators also approved the change with 52.7% support, just over the 51% requirement, Decrypt reported. Stake pool operators run the servers that help keep Cardano operating.

The network’s Constitutional Committee also signed off. Decrypt described the committee as a seven-member body that checks whether proposed changes comply with Cardano’s founding document.

Cardano had been building toward this setup through earlier upgrades. The Chang hard fork in 2024 introduced on-chain voting, and the Plomin hard fork in early 2025 gave token holders more direct decision-making power, according to Decrypt.

What changes for developers

The Van Rossem hard fork is an intra-era upgrade, meaning it changes specific parts of the protocol without redesigning Cardano’s overall structure. Its main technical goal is reducing Plutus execution costs.

Plutus is Cardano’s smart contract programming language. Smart contracts are programs that run on a blockchain and power tools such as decentralized finance apps, NFT marketplaces and on-chain payments. Lower execution costs can let developers build more complex applications while using fewer network resources.

Input Output Group said on X that protocol version 11 adds constant-time array indexing, native Value handling, faster list traversal and new cryptographic primitives. Cryptographic primitives are basic security tools used to verify and protect blockchain activity.

Input Output Group also said the new built-ins work across Plutus V1, V2 and V3, while the transaction shape stays the same.

Decrypt reported that the upgrade includes five technical improvements, including tools for faster digital signature verification and a security fix requiring each stake pool to use a unique cryptographic key. That change is intended to close a known attack path.

Why the name matters

The upgrade is named for Max van Rossem, a Dutch Cardano contributor who died in October 2025, according to Decrypt. Van Rossem worked as a developer, elected representative, node operator and constitutional delegate, and helped design the governance process used to approve the upgrade.

ADA traded at $0.16827, up 2.03%, according to price data shown by Decrypt. As with any crypto network upgrade, the market reaction can differ from the technical impact, especially when the main change affects developer costs and governance rather than immediate user-facing features.

This story draws on original reporting from Decrypt.