Ouroboros 101 – Understanding The Protocol

Ouroboros is the fundamental protocol of Cardano which enables the decentralized public blockchain and thus cryptocurrency to function.

By deliberately bringing together a combination of peer review, formal verification, and functional programming languages, a specification-defined cryptocurrency, one that’s provably secure in fact, was born. This contrasts greatly with the likes of Bitcoin for example, as those are merely implementation-defined, which means they do not have anywhere near the same level of assurance when the code is released.

With that, below we will cover the different versions and variants of Ouroboros starting from the high-level scientific research and formal specification, through to the implementation in program code, and all the way down to the final roll-out phases.

Ouroboros' Development 2 Minute audio-multimedia presentation

Scientific Research Engineering Development Roll-out 2016 2017 2018 2019 2020 2021 Classic testnet federated mainnet Byron Praos BFT Genesis testnet decentralized mainnet BFT Shelley Crypsinous Hydra ... Philos ...

Each Ouroboros version had its beginning in a scientific study, and was peer-reviewed at the world’s most prestigious cryptography conferences. The corresponding part will be handed over to the software development department as soon as the result can be evaluated as safe according to theoretical and scientific standards. Finally, finished programs are rolled out into the test network and then into the operative Mainnet. So over the years different Ouroboros versions and functions have been developed. The first “Classic” version showed that with “Proof of Stake” you can achieve security features comparable to Bitcoin. This was implemented in a federated test and main network and put online in September 2017. This is the so-called Byron phase, in which transactions were already possible, but at the same time further research and improvements followed. For example Prhaos to provide security against deliberate corruption of adversaries, or BFT as a deliberately simple intermediate step to Shelley and Ouroboros Genesis, which enables new or offline parties to safely re-join and bootstrap their blockchain from the genesis block without any trusted advice The results of this research are now in the implementation phase, which will take place in parallel in Haskell and Rust in order to implement the Test- and Mainnet in 2019. There will be a short BFT transition phase with planned hard forks before the decentralized Shelley phase begins. The research department is already working on the next new components to gradually complete the Cardano protocol. For example Ouroboros Crypsinous, the first formally analyzed privacy-preserving proof-of-stake blockchain protocol, or Hydra and Philos. And that sumarizes the Ouroboros protocol and all of it’s developments. Stay up to date for more Protocol details by subscribing to our newsletter, Twitter or Telegram channels.

Photo credits to Jonathan Francisca