Cardano Unveils Two-Phase Dijkstra Upgrade with Leios and Peras

Cardano is planning a two-phase Dijkstra upgrade, which will bring significant improvements to its network. The first phase, targeted for Q4 2026, will introduce Ouroboros Linear Leios and increase throughput through supplementary Endorser Blocks alongside existing Praos Ranking Blocks.

The new blocks will reference additional transactions that the network can process after certification by a stake-based committee. This change is expected to increase transaction capacity without relying on larger blocks or faster slots.

In addition, Phase 1 of the Dijkstra upgrade will introduce several other changes, including nested transactions, guard scripts, and account-address improvements. These changes are designed to support the updated ledger and transaction structures.

The second phase of the Dijkstra upgrade is planned for Q2 2027 and will activate Ouroboros Peras. This change will add a voting overlay to the existing Praos chain selection mechanism, allowing stake-pool committees to vote on recent chain tips and reach settlement sooner.