Upgrade lowers smart contract costs, sets stage for Ouroboros Leios
Cardano activated the van Rossem hard fork on Saturday, upgrading its mainnet from Protocol Version 10 to Version 11. The upgrade marks the first governance-driven hard fork in Cardano’s history, a shift from previous upgrades coordinated by Input Output, the engineering company that designed and built Cardano.
The hard fork transitioned the network at epoch 644. According to Input Output, the upgrade includes Plutus improvements and Plutus Cost Model enhancements intended to lower smart contract execution costs on the blockchain.
“As well as Plutus improvements and Plutus Cost Model enhancements, this upgrade lays the foundation for the next upgrade, the Dijkstra era hard fork, which will introduce Ouroboros Leios to Cardano,” Input Output stated.
Ouroboros Leios is a scaling proposal designed for the Ouroboros proof-of-stake consensus mechanism that secures Cardano. The upgrade aims to drastically increase transactions per second without weakening Ouroboros’ security guarantees. Input Output expects to launch Ouroboros Leios in late 2026 as part of the Dijkstra era hard fork.
The governance-driven nature of the van Rossem fork represents a structural change in how Cardano upgrades its protocol. Previous hard forks were coordinated directly by Input Output rather than through community governance processes.
Separately, the Cardano Foundation canceled its annual conference after a failed funding vote, though this decision was unrelated to the hard fork activation.
