Tldr:
- Cardano’s Van Rossem hard fork is the first upgrade to be fully approved by onchain governance.
- Protocol version 11 unifies built-in Plutus functionality across the V1, V2, and V3 networks.
- Five new CIPs add standard exponential, matrix types, and BLS12-381 multilevel multiplication.
- The hard fork honors Max van Rossem, the Dutch Cardano governance creator who died in 2025.
Cardano Complete It is a Van Rossem hard fork, triggering version 11 of the protocol across the mainnet network. The Cardano Hard Fork represents the first upgrade approved entirely by onchain governance, without relying on central coordination.
Named after the late Dutch community leader Max van Rossem, the update introduces new Plutus primitives, unified built-in functionality, and ledger-level improvements.
The Cardano hard fork also reduces smart contract execution costs while preparing the network for the upcoming Dijkstra era.
The governance process behind the Cardano hard fork
Van Rossem upgrade moved file Cardano mainnet from protocol version 10 to version 11. The change occurred through an intra-era hard fork, keeping the ledger in the Conway era. No squeezing occurred during this process.
The Intersect hard fork working group recommended governance action on June 15, 2026. The technical steering committee endorsed the recommendation a day later. The two bodies confirmed that the proposal meets the technical standards required before submission.
The Cardano constitution requires at least 85% of the stake pools by active stake to upgrade the node software in advance.
The relevant guardrails stipulate that the stock pools must move to ‘A’. The version of the Cardano node capable of processing rules“Linked to the new protocol version. This threshold has been verified by the Constitutional Committee and equity pool operators.
Test reports confirmed no behavioral regressions across the network. Full compatibility between the specifications and implementation of the new ledger rules has been demonstrated. Performance standards for Cardano node Version 11.0.1 did not show any regressions compared to previous versions.
New Plutus abilities introduced
Five proposals to improve Cardano made the beginnings of the new Plutos through this hard fork. These include CIP-0109, CIP-0132, CIP-0133, CIP-0138, and CIP-0153. Each proposal targets a specific performance or functionality gap in the smart contract implementation.
The CIP-0109 adds a built-in standard exponential, supporting cryptographic operations such as elliptic curve calculations.
The CIP-0132 offers drop-down menu functionality, improving access to menu items and indexing efficiency of the feeder. The CIP-0133 enables multi-level multiplication via the BLS12-381, which supports Proof of zero knowledge On-chain verification.
CIP-0138 introduces a new type of array with fixed-time indexing to Plutus Core. This replaces the previous singly linked list structure for many use cases. CIP-0153 introduces a native value type, simplifying the handling of multi-asset tokens within smart contracts.
After the hard fork, all built-in functionality is available via Plutus V1, V2, and V3. Untyped Plutus Core also gained case expressions for the Bool, Integer, and Data types. This replaces more expensive conditional styles that previously slowed down script execution.
Ledger improvements and tribute to Max van Rossem
The hard fork enhanced several ledger-level protections during this update. The uniqueness of the VRF key hash is now enforced at the ledger level, preventing duplicate stake pool records. This change mitigates some of the attack vectors associated with VRF key reuse.
Reference input rules for Plutus V1 and V2 scripts have also been revised. Voting entries in the Constitutional Committee have been upgraded from diary checks to ledger predicates. This change improves transparency across all transaction submission paths.
The hard fork is named after Max van Rossem, a Dutch community creator who died in October 2025.
He co-led the Constitutional Committee Elections Working Group and represented the Dutch community at the Constitutional Convention in Buenos Aires.
Van Rossem founded AdaMoments and later Moments, guided by the belief that “user data = user data.” His son, Max Louis Hans van Rossem, was born on January 11, 2026. Cardano hard fork He now carries his father’s name in the network’s enduring history.
