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RFC 4122 UUIDs

.. toctree::
    :titlesonly:
    :hidden:

    rfc4122/version1
    rfc4122/version2
    rfc4122/version3
    rfc4122/version4
    rfc4122/version5

RFC 4122 defines five versions of UUID. Each version has different generation algorithms and properties. Which one you choose to use depends on your use-case. You can find out more about their applications on the specific page for that version.

Version 1: Time-based
This version of UUID combines a timestamp, node value (in the form of a MAC address from the local computer's network interface), and a clock sequence to ensure uniqueness. For more details, see :doc:`rfc4122/version1`.
Version 2: DCE Security
This version of UUID is the same as Version 1, except the clock_seq_low field is replaced with a local domain and the time_low field is replaced with a local identifier. For more details, see :doc:`rfc4122/version2`.
Version 3: Name-based (MD5)
This version of UUID hashes together a namespace and a name to create a deterministic UUID. The hashing algorithm used is MD5. For more details, see :doc:`rfc4122/version3`.
Version 4: Random
This version creates a UUID using truly-random or pseudo-random numbers. For more details, see :doc:`rfc4122/version4`.
Version 5: Named-based (SHA-1)
This version of UUID hashes together a namespace and a name to create a deterministic UUID. The hashing algorithm used is SHA-1. For more details, see :doc:`rfc4122/version5`.