Babylon: Reusing Bitcoin Mining to Enhance Proof-of-Stake Security
This addresses security vulnerabilities for blockchain developers and users by combining energy efficiency with enhanced security, though it is an incremental approach building on existing mining infrastructure.
The paper tackles the security issues of Proof-of-Stake blockchains, such as susceptibility to attacks and bootstrapping difficulties, by proposing Babylon, a platform that reuses Bitcoin's hash power to enhance PoS security with zero additional energy cost, formalized through a cryptoeconomic security theorem.
Bitcoin is the most secure blockchain in the world, supported by the immense hash power of its Proof-of-Work miners, but consumes huge amount of energy. Proof-of-Stake chains are energy-efficient, have fast finality and accountability, but face several fundamental security issues: susceptibility to non-slashable long-range safety attacks, non-slashable transaction censorship and stalling attacks and difficulty to bootstrap new PoS chains from low token valuation. We propose Babylon, a blockchain platform which combines the best of both worlds by reusing the immense Bitcoin hash power to enhance the security of PoS chains. Babylon provides a data-available timestamping service, securing PoS chains by allowing them to timestamp data-available block checkpoints, fraud proofs and censored transactions on Babylon. Babylon miners merge mine with Bitcoin and thus the platform has zero additional energy cost. The security of a Babylon-enhanced PoS protocol is formalized by a cryptoeconomic security theorem which shows slashable safety and liveness guarantees.