How to use CFUUID, can CFUUID be traced back to a unique individual. security/privacy

Question

i an new to iphone Dev and the concept of CFUUID, so thought i should ask, before i start implementing it. so the string returned by CFUUID is it really unique or can it be traced back to a unique individual. meaning lets say, i generate a CFUUID object and convert it to string(using the methods provided) , and then this info is used in my app or stored on a server database. and how unique is it, i mean is their a chance it can be similar to one generated on some other device. is it a good idea to use this info freely or are their some security/privacy aspects that i am not thinking about here. any help is greatly appreciated thanks

Answer 1

The CFUUID does contain the ethernet address of the device, so it's appropriate to have some privacy concerns about how you store/publish them. They can't be directly traced to a person, but they certainly can be traced to a specific device.

The UUID format is documented in RFC4122, and you can also view the source code of Apple's CFUUID implementation.

Answer 2

The overview in the CFUUID Reference explains your concerns and generalizes how the unique identifiers are generated. There are no special security concerns when generating a UUID, they do not necessarily "point" to any specific device, although some hardware reference is used in their generation to help ensure that they are unique (again, as stated in the overview). There is nothing especially cryptographic about them.