UUID v4 generator
UUID v4 generator
A UUID (Universally Unique Identifier) is a 128-bit identifier that is designed to be globally unique and generated with very low likelihood of collisions. UUIDs are commonly used to uniquely identify objects, entities, or resources in computer systems and applications. They are particularly useful in distributed systems where multiple entities need to generate identifiers without the need for centralized coordination.
There are different versions of UUIDs, each with a different structure and method of generation. UUID version 4 (UUIDv4) is one of the most commonly used versions. It is defined in RFC 4122 and is sometimes referred to as a "random UUID." UUIDv4 is generated using a combination of random numbers or pseudorandom numbers and the MAC address of the computer's network interface card (NIC).
Here's a breakdown of the components of a UUIDv4:
- Version (4 bits): The version number that specifies the UUID version. In UUIDv4, this is always "0100".
- Variant (2 bits): The variant of the UUID. For UUIDv4, this is set to "10" to indicate the variant defined in RFC 4122.
- Timestamp (60 bits): In UUIDv4, this part is generated using random or pseudorandom numbers to ensure uniqueness.
- Node (48 bits): The MAC address of the computer's NIC, if available. If the MAC address is not available or cannot be accessed, this part is generated using random or pseudorandom numbers.
The use of random or pseudorandom numbers in UUIDv4 generation is intended to provide a high degree of randomness and ensure that UUIDs are unlikely to collide, even in distributed systems. However, it's important to note that the randomness of UUIDv4 is subject to the quality of the random number generator being used. In applications where cryptographic security is crucial, it's recommended to use a cryptographically secure random number generator.
UUIDv4 is widely supported across programming languages and platforms and is often used in various applications, including database systems, distributed systems, and web applications, where unique identifiers are needed.