UUID Generator (version 5)

Generate a Universally Unique IDentifier (UUID) version 5 (name-based, SHA-1), a deterministic 128-bit identifier derived from a namespace and name. The same inputs always produce the same UUID.

Generated UUID:

 

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More about UUID version 5

UUID version 5 is a name-based UUID that uses SHA-1 hashing to produce a deterministic identifier from a namespace UUID and a name string. Here is how a UUID version 5 is constructed:

  1. A namespace UUID is selected. RFC 4122 defines four well-known namespaces: DNS (6ba7b810-9dad-11d1-80b4-00c04fd430c8), URL (6ba7b811-9dad-11d1-80b4-00c04fd430c8), OID (6ba7b812-9dad-11d1-80b4-00c04fd430c8), and X.500 (6ba7b814-9dad-11d1-80b4-00c04fd430c8).

  2. The namespace UUID bytes (16 bytes) are concatenated with the name string bytes (encoded as UTF-8).

  3. The concatenated data is hashed using the SHA-1 algorithm, producing a 20-byte (160-bit) digest.

  4. The first 16 bytes of the hash are used to form the UUID. The version number 0101 (5 in hexadecimal) is set in the most significant 4 bits of the 7th byte, and the variant 10 is set in the most significant 2 bits of the 9th byte.

The resulting UUID has the format: xxxxxxxx-xxxx-5xxx-yxxx-xxxxxxxxxxxx, where the 5 indicates version 5 and y represents the variant. Because UUID v5 is deterministic, the same namespace and name will always produce the same UUID, making it useful for generating consistent identifiers from human-readable names.