Overview

Space and Time is a permissionless L1 blockchain purpose-built to function as a decentralized database and query coprocessor for smart contracts. The protocol enables developers or indexer nodes to insert structured data into tamperproof relational tables, and then execute SQL queries against that data with zero-knowledge (ZK) proof guarantees. Inserting data is just an ED25519/ECDSA-signed transaction executed on SXT Chain.

Every data insert is verified and committed using a cryptographic digest of the table’s contents, signed by a quorum of Validator nodes under Byzantine Fault Tolerant (BFT) consensus. These table-level commitments ensure that all rows stored in Space and Time are immutable, auditable, and cryptographically verifiable when:

1. Validators update a table's cryptographic commitment as new rows are inserted via signed EDDSA or ED25519 Substrate transactions.
2. Validators leverage BFT consensus to threshold-sign the updated commitment before storing them onchain.

These commitments act as cryptographic fingerprints of the table’s data (almost analogous to a Merkle tree of the table's contents). The commitments are required later during ZK proof of SQL queries, as the prover uses them to ensure the underlying tables have not been tampered.

The design of Space and Time's ZK-proof generation on both data commitments and SQL logic allows Space and Time to prove two things with a single ZK-proof:

• The data in the underlying tables have not been manipulated, and
• The actual SQL query execution (the computations) have been performed correctly

Query execution typically occurs offchain via a decentralized network of Prover nodes, which compute SQL results and generate ZK proofs attesting to both the correctness of the computation and the integrity of the underlying data. These proofs can be verified by onchain EVM contracts or by offchain clients (e.g., web apps, wallets) without revealing any sensitive data.

Space and Time (SXT Chain) is the first trustless database for the EVM, enabling smart contracts to interact with historical, cross-chain, or offchain data as if it were natively accessible onchain. Space and Time (SXT Chain) is optimized for:

• High-throughput data ingestion from blockchains, consumer apps, and enterprise sources
• Verifiable query execution over large datasets (millions of rows)
• Fast ZK proof generation and EVM-compatible proof verification with minimal gas