ISO/IEC 18670:2025

This specification defines a standard data format for referencing software artifacts that match the data model of modern distributed version control systems. This format includes the typical tree-like structure of a filesystem hierarchy, but also, special nodes to track revisions and releases, as well as the full status of a version control system, with all its development branches. A key property of SWHIDs is that they can be computed using cryptographically strong functions directly from the digital objects they refer to, by anyone that has access to a copy of those objects. This enables decentralised and independent verification of integrity, without relying on a registry or a central authority. The computation of the SWHID identifiers is based on Merkle Acyclic Directed Graphs, a natural generalization of Merkle trees. The resolution of SWHIDs, that is, the process of obtaining a copy of a digital artifact corresponding to a given SWHID, is outside the scope of this specification.