Hi, 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
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216answers:
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A:
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.
Jason Coco
2010-04-15 02:32:29
ya, i was not sure, i wanted to make sure i understand it right. my big concern here is that, if someone got hold of one can they reverse the process and get back to the original information that they should not have. what i want to do is use it like a user ID of sorts and then as a URL variable. i thought it might be a good for it as it it unique and so has lots of combos.
Kevin
2010-04-15 06:38:49
A:
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.
David Gelhar
2010-04-15 03:03:11
from the documentation, it does seem that it can be guessed and should not be used for security. what i wanted to do was use it as one of the URL variables, and thought that since it would be unique it would be pretty good and would be hard to come up with it, there being so many combos possible.
Kevin
2010-04-15 06:07:03