BlockCommon

BlockCommon is a specification and reference implementation designed to standardize the structure, metadata, and exchange protocol for blocks used in distributed ledger systems. It provides a canonical block format, a minimal protocol layer, and a set of interoperability guarantees so that data blocks created on one network can be validated and interpreted on another. The aim is to facilitate cross-ledger data sharing, improve verifiability, and reduce integration costs while preserving cryptographic integrity and auditability.

BlockCommon originated from a community-driven initiative begun in the early 2020s by researchers, developers, and vendors in the distributed ledger field. It is stewarded by the BlockCommon Foundation, with contributions from participating projects and independent contributors. The specification and reference implementations are published openly under a permissive license to encourage broad adoption and interoperability testing.

Key features include a canonical block header (block_id, previous_hash, timestamp, and merkle_root), a payload area for transactions or records, and optional privacy controls such as selective disclosure and encryption. The standard supports multiple payload encodings, versioning for backward compatibility, and a reference conformance suite to verify interoperability across implementations. A cross-network referencing capability allows blocks to point to equivalent data on partner ledgers, enabling cross-chain queries and audits.

Adoption remains diverse, with several blockchain platforms and distributed databases offering BlockCommon-compatible adapters or modules. Typical use cases span cross-ledger asset tracking, supply chain provenance, and interoperable identity data.

Limitations include potential performance overhead, schema complexity, and the need for aligned governance across participating networks to ensure consistent interpretations of the block data.