Today we release Cardano 1.5 on the Cardano mainnet. The Cardano 1.5 release is a milestone because it is the last major Cardano release of the Byron development phase, which we have been in since the launch of mainnet.

Cardano 1.5 is important in preparation for moving to the Shelley development phase. This update brings a new consensus protocol, Ouroboros BFT, which is a key step in the transition from Ouroboros Classic, the current consensus protocol running the Cardano network, to Ouroboros Genesis, the protocol for the Shelley era. Ouroboros Genesis is a major upgrade to the protocol that underpins Cardano because it is first proof-of-stake protocol that matches the security guarantees of proof-of-work protocols such as Bitcoin.

Ouroboros BFT will not be immediately activated after deployment of the 1.5 release. It will be activated through a protocol update later, which will be announced separately. This protocol update will deactivate the Ouroboros Classic protocol and activate the Ouroboros BFT consensus protocol. This update is technically a hard fork but will take place in a smooth and automatic way because this is a planned protocol upgrade whereby all parties of the current federated system have agreed to the change.

Daedalus users need to upgrade to Cardano 1.5 by installing Daedalus 0.13.0 by following prompts in Daedalus. Everyone needs to upgrade to version 1.5 in order to make the hard fork.

Please be aware of fraudsters posting fake Daedalus apps online or making attempts through social media or private message to gain access to your wallet. Always download Daedalus only from official sources.

Cryptocurrency exchanges need to migrate from v0 to v1 wallet API before upgrading to this release. The v0 wallet API, which was deprecated in the 1.4 release, is now completely removed in the 1.5 release and can no longer be used.

The Cardano 1.5 release also makes many other improvements. These include performance improvements when rendering lists with a large number of transactions and wallet addresses, the addition of features for detecting insufficient disk space, and a new screen that visualizes the block storage consolidation process.

For more information please see the release notes.