Cardano plans two-phase Dijkstra upgrade with Leios and Peras

Cardano is working on a major protocol upgrade that is being rolled out in two phases under the name Dijkstra. Phase 1, aimed at code completion in the fourth quarter of 2026, activates Ouroboros Linear Leios to increase transaction speed. Phase 2, scheduled for the second quarter of 2027, adds Ouroboros Peras, a voting layer for stake pools intended to shorten transaction settlement time. Both phases will first go through test networks and require approval via on-chain governance before activation on the mainnet.

Cardano is available at OKX and Bybit.

In short:

• Phase 1 of the Dijkstra upgrade focuses on higher transaction throughput via Ouroboros Linear Leios, scheduled for Q4 2026.
• Phase 2 activates Ouroboros Peras in Q2 2027, intended to settle transactions faster via a voting layer for stake pools.
• Both phases require testnet rollout and approval via on-chain governance before the mainnet is updated.

Phase 1: higher transaction throughput with Linear Leios

The first phase introduces a new block type alongside the existing Praos blocks. So-called Endorser Blocks contain references to extra transactions that do not fit in a regular block. A committee of stake pools certifies these Endorser Blocks, after which the transactions are processed in the network. In this way, the network can process considerably more transactions per unit of time without the base blocks becoming larger or slots becoming faster.

In addition to Linear Leios, phase 1 also includes nested transactions (CIP-118), which allow a transaction to contain child transactions with their own signatures and execution contexts. Furthermore, there will be so-called guard scripts (CIP-112), improvements to account addresses (CIP-159) and a simplification of staking reward withdrawals (CIP-181). According to the Intersect Product Committee, phase 1 also lays the technical foundation for phase 2 by already introducing the required block structure changes and protocol parameters.

Phase 2: faster settlement via Peras

The second phase activates Ouroboros Peras via a so-called intra-era hard fork, a protocol version update within the Dijkstra era that does not require a fully new era package. Peras adds a voting layer in which stake pools vote to finalise transactions more quickly. Because phase 1 already introduces the required block structures and parameters for Peras, no new era is needed for activation in phase 2.

The rollout strategy follows the same order each time: first the Preview testnet, then the Pre-production testnet and finally the mainnet. On the mainnet, DReps, stake pool operators and the Constitutional Committee vote on the governance action before the hard fork takes effect. A concrete date for activation on the mainnet has not yet been set. All the stated quarterly targets are estimates for code completion and do not yet include time for governance processes and community testing. Cardano is currently at $0.18, down 1.0% in the past 24 hours.