Random UUID version 4
02UUIDv4 fills the available layout with random data around fixed version and variant bits.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 5.4 ↗
RFC 9562 · § 5.4EXAMPLE
3 / 3
03
Issue the identifier
Keep the identifier distinct from an authentication secret.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
Read the updated RFC section ↗
The version and variant leave 122 random bits.
- The version and variant leave 122 random bits.
- Use a suitable random source; CSPRNG guidance appears in §6.9.
- Collisions remain probabilistic rather than mathematically impossible.
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.
Privacy