A study undertaken by a group of student researchers has found vulnerabilities within proof-of-stake cryptocurrencies affecting up to 26 coins, however, it appears Cardano (ADA) is not one of them! Cardano appears to be invulnerable to these types of attacks, due to the fact that the project team built ADA from the ground up rather than simply using an existing model, such as Bitcoin’s UTxO model. And not only does Cardano have a fundamentally different foundation, but that foundation is the result of multiple peer-reviewed academic papers, and an unprecedented collaboration between researchers and developers.
More on the study can be found here:
Read IOHK’s blog post on Cardano’s security against fake-stake attacks here: