As Web3 technology rapidly evolves, it faces several key challenges on its path to widespread adoption: poor user and developer experiences, the fragmentation of blockchain ecosystems (and associated zero knowledge toolkits), and the inherent limitations of smart contracts in processing data. To achieve the vision of Web3—a world where business logic and value exchange are underpinned by verifiability rather than trust—these obstacles must be addressed. Space and Time Labs has developed a groundbreaking zero-knowledge circuit—Proof of SQL—that aims to tackle these issues.
Space and Time's ZK coprocessor provides high-efficiency query processing, accelerating the time-to-value for dApp developers and enhancing the end-user experience. Acting as a single source of truth for the state of every popular blockchain, the coprocessor supplements the limited storage and computational power of smart contracts using verifiable SQL queries. This allows dApp developers to construct sophisticated, data-driven, cross-chain smart contracts—fulfilling the vision of Web3.
The Proof of SQL protocol introduces an innovative ZK proof that extends the security of Ethereum and other major L1, L2, or L3/appchain to SQL databases. The protocol cryptographically guarantees that the requested data (often indexed blockchain data but can also verify off-chain data) is tamper-proof and that the computational steps of the query request have been executed accurately. Proof of SQL eliminates the inefficiencies associated with consensus-driven data processing and offers practical, low-latency proof generation at a scale suitable for enterprise-grade applications. According to benchmarks conducted by Space and Time, proof generation for a million-row table executed on a single NVIDIA GPU takes less than 3 seconds.
When data is indexed into the Space and Time data warehouse, it is secured with a Byzantine Fault Tolerance (BFT) consensus algorithm to ensure the data is cryptographically proven/verified before it is used for queries. For example, a client can define an immutable table in the Space and Time data warehouse to continuously store stock prices from traditional stock markets, capturing real-time price information from twelve different stock market data APIs through external business logic. Space and Time transaction nodes can reach consensus on the Apple stock price across twelve different data providers and insert only the threshold-signed, consensus-approved price into the shared storage (which exists as public good within Space and Time). To increase security, a library was developed that data providers can utilize to cryptographically sign data at the source, which the validators integrate during the proving process against the underlying data.
The decentralized data warehouse acts as a critical resource that allows smart contracts to offload computation and data storage efficiently. This solution enhances the scalability of the chain, making smart contract execution faster and reducing the amount of gas spent on-chain while keeping the entire stack decentralized and community-owned. In alignment with the decentralized spirit of Web3, the nodes that constitute the data warehouse platform must be community-owned and operated, enabling data storage and processing to occur within a network of nodes owned and operated by the community. Through role-based and row-based access controls, governance of each table/ledger in the data warehouse is facilitated, using "cookies" to encode user secrets and share permissions around CRUD operations. This also promotes self-custody of data within Space and Time, allowing end-users to directly write to "public write permission" tables/ledgers without intermediaries and subsequently remove content or manage how dApps accessing these tables/ledgers consume the content.