Name-based and custom layouts
04Name-based UUIDs combine a namespace with a name; other versions serve different goals.
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Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 5.5 ↗
RFC 9562 · § 5.5EXAMPLE
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03
Respect layout semantics
Do not treat every UUID version as interchangeable random data.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
Read the updated RFC section ↗
Version 5 uses SHA-1 over namespace and name as defined by its layout.
- Version 5 uses SHA-1 over namespace and name as defined by its layout.
- Version 6 reorders time-based fields; version 8 provides a custom layout with required version/variant bits.
- A deterministic UUID does not prove that the underlying name is authentic.
Examples are illustrative. Consult the linked RFC and its errata for implementation details.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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