# Stake-Bleeding Attacks on Proof-of-Stake Blockchains (2017) ###### tags: `Security`, `PoS`, `Cardano` Authors Universities of Edinburgh & Connecticut, IOHK (company behind the Cardano blockchain) ## Summary This paper puts forward a potential flaw in proof-of-stake protocols : a sub-type of long-range attack. In a long-range attack, the bad guy intents to modify most of, if not all, the blockchain. To do so, he acquires the private keys of former stakeholders that, when put together, owned at a specific time 51% the of the stake. He then creates a parrallel blockchain from this particular moment. ## Comments Quite serious and , but very specific to the proof-of-stake protocol. Probably not worth reading if it's outside of your theme.