Generate name and namespace-based UUID v3, using MD5 hash algorithm.
Note: The same namespace and name will always generate the same UUID
Introduction to UUID v3
UUID v3 is a unique identifier generated based on name and namespace, using MD5 hash algorithm. It can generate consistent UUIDs for the same name and namespace combination.
Namespace and name
UUID v3 requires two inputs: a namespace UUID and a name string. Commonly used predefined namespaces include DNS, URL, OID, and X.500 DN, custom namespaces can also be used.
v3 vs v5
UUID v3 and v5 are both name-based UUIDs, with the main difference being the hash algorithm used. v3 uses MD5, while v5 uses SHA-1. v5 offers better security, but v3 may be more efficient in certain environments.
Use cases
UUID v3 is suitable for scenarios requiring determinism and repeatability, such as generating permanent IDs from usernames or assigning fixed identifiers to resources. Any situation where the same input must always produce the same UUID is a good fit for v3.
Security considerations
Although UUID v3 uses MD5 hashing, it is generally safe when used as an identifier. However, if security is a major concern, it is recommended to use SHA-1-based UUID v5, as MD5 has been proven cryptographically insecure.
Predefined namespaces
The UUID specification defines four standard namespaces: DNS (6ba7b810-9dad-11d1-80b4-00c04fd430c8), URL (6ba7b811-9dad-11d1-80b4-00c04fd430c8), OID (6ba7b812-9dad-11d1-80b4-00c04fd430c8), and X.500 DN (6ba7b814-9dad-11d1-80b4-00c04fd430c8).