On 26th July, IOHK published a video, in which Dr. Peter Gazi, a researcher of the foundation explains two specific versions of Ouroboros protocols and how they relate to each other.
According to him, the first Ouroboros protocol was published in the year 2017, which is presently underlying the implementation of the Cardano network. However, soon other protocols were being developed to improve the security guarantees.
Peter states that the immediate version to the original protocol is Ouroboros Praos, which was designed to give stronger security guarantees when it came in contact with stronger adversaries. These adversaries were capable of delaying messages as well as having a certain degree of control over the network. They also had more control over corrupting certain parties who participate in the protocol and control over the delivery of protocol messages to the honest parties.
The most recent version of the protocols is the Ouroboros Genesis, which gives more insight on how these protocols work together to provide more functionality on top of the blockchain that is running on this proof-of-stake system, says Peter.
He further adds that it also addresses an important problem of Bootstrapping from Genesis.
He describes this as:
“A secure way how a party that wants to join the protocol later, can do that securely with only having a trusted copy of the Genesis block but no need for particular guaranteed checkpoint.”
Peter finally says that he strongly believes that Proof-of-stake is the right approach to maintain a blockchain as opposed to ways that require physical resources such as proof-of-work or proof-of-space and variants of it.