Which UUID version to use?

by

There are two different ways of generating a UUID.

If you just need a unique ID, you want a version 1 or version 4.

  • Version 1: This generates a unique ID based on a network card MAC address and current time. If any of these things is sensitive in any way, don’t use this. The advantage of this version is that, while looking at a list of UUIDs generated by machines you trust, you can easily know whether many UUIDs got generated by the same machine, or infer some time relationship between them.

  • Version 4: These are generated from random (or pseudo-random) numbers. If you just need to generate a UUID, this is probably what you want. The advantage of this version is that when you’re debugging and looking at a long list of information matched with UUIDs, it’s quicker to spot matches.

If you need to generate reproducible UUIDs from given names, you want a version 3 or version 5. If you are interacting with other systems, this choice was already made and you should check with version and namespaces they use.

  • Version 3: This generates a unique ID from an MD5 hash of a namespace and name. If are dealing with very strict resource requirements (e.g. a very busy Arduino board), use this.

  • Version 5: This generates a unique ID from an SHA-1 hash of a namespace and name. This is the more secure and generally recommended version.

More Related Contents:

  1. Generating v5 UUID. What is name and namespace?
  2. What is a UUID?
  3. PHP function to generate v4 UUID
  4. How unique is UUID?
  5. How good is Java’s UUID.randomUUID?
  6. How to preserve identifierForVendor in ios after uninstalling ios app on device?
  7. How to get a unique device ID in Swift?
  8. Advantages and disadvantages of GUID / UUID database keys
  9. Is there any difference between a GUID and a UUID?
  10. Likelihood of collision using most significant bits of a UUID in Java
  11. How should I store GUID in MySQL tables?
  12. How to test valid UUID/GUID?
  13. Generating a UUID in Postgres for Insert statement?
  14. How do I create a GUID / UUID?
  15. How to store uuid as number?
  16. UUID performance in MySQL?
  17. Using a UUID as a primary key in Django models (generic relations impact)
  18. Is Secure.ANDROID_ID unique for each device?
  19. Android: How do bluetooth UUIDs work?
  20. Generating 8-character only UUIDs
  21. A TypeScript GUID class? [closed]
  22. How can I generate UUID in C#
  23. Collision probability of ObjectId vs UUID in a large distributed system
  24. XSLT generate UUID
  25. Collisions when generating UUIDs in JavaScript
  26. How to generate a random UUID which is reproducible (with a seed) in Python
  27. How to generate a UUIDv4 in MySQL?
  28. How to make unique short URL with Python?
  29. How to generate a version 4 (random) UUID on Oracle?
  30. How to find the UUID of serial port Bluetooth device?

Leave a Comment