LETUS: A Log-Structured Efficient Trusted Universal BlockChain Storage

With the evolution of Web3.0 and decentralized applications (Dapps), increasing business logic is running on the blockchain. Blockchain storage, as the core infrastructure supporting the increasing volume of data, plays a crucial role. However, the performance and cost of blockchain storages are suffering seriously, which inspires us to re-examine the design of blockchain storage based on the blockchain data characteristics. We propose LETUS, a Log-structured Efficient Trusted Universal Storage for blockchain, providing cryptographic tamper evidence with excellent performance and resource efficiency. (1) LETUS breaks the traditional two-layered architecture and pushes down the Authenticated Data Structure (ADS) into the storage engine to enable fine-grained I/O optimizations. (2) LETUS proposes DMM-Tree which is a novel ADS combining the functionalities of Merkle tree and delta-encoding, significantly reducing storage consumption. (3) LETUS adopts a version-based indexing schema and manages the large volume of pages generated by ADS in a page store indexed by a B-tree variant. (4) LETUS provides a universal solution for different blockchains, such as public blockchains like Ethereum, BNB Smart Chain and AntChain as a representation of consortium blockchains. LETUS has been deployed in AntChain commercial applications, such as NFT and digital torch ignition for 2023 Asian Games. Experimental results also show that with LETUS, AntChain can achieve up to 15.8x improvement in throughput and 80.3% storage cost saving, Ethereum can achieve up to 10.1x improvement in throughput and 75.0% storage cost saving.