A team of Us researcher discovered that 26 proof of stake (POS) cryptocurrencies are vulnerable at “Fake Stake” attacks.
This study declares :”Proof-of-Stake (PoS) cryptocurrencies, particularly those based on chain-based PoSv3 (Proof-of-Stake version 3), are similar to Bitcoin in that they use the UTXO model and longest chain consensus rules.
The key difference is that they replace the Proof-of-Work with proof-of-ownership of coins. Potential benefits of the PoS approach range from reducing environmental impact to better security against 51% attacks.
Many cryptocurrencies are in fact forks (or at least descendants) of Bitcoin’s codebase, with the PoS functionality grafted in. However, some design ideas are copied over insecurely, leading to new vulnerabilities that did not exist in the parent codebase.We call the vulnerabilities we found “Fake Stake” attacks.
Essentially, they work because PoSv3 implementations do not adequately validate network data before committing precious resources (disk and RAM). The consequence is that an attacker without much stake (in some cases none at all) can cause a victim node to crash by filling up its disk or RAM with bogus data.
We believe that all currencies based on the UTXO and longest chain Proof-of-Stake model are vulnerable to these “Fake Stake” attacks”.
This study list this 26 cryptocurrencies.
Cardano on January 29, in a post declared they are not vulnerable.
Cardano is different because IOHK took a different approach. Instead of finding a minimal variation of bitcoin, IOHK Team created a new protocol and the result is Ouroboros protocol.
In this protocol, validating that a block has been signed by the right stakeholder is also simple: it requires only the leader schedule for the current epoch (which will not change in case of a temporary fork), and the checking of a signature.
This can and will be done by each node once they get the block header, in contrast to the PoSv3 systems that are vulnerable to fake stake attacks.
In short Cardano is secure against fake stake attacks because it’s based on a fundamentally different system.
Investors can rest easy tonight.