问题
I want to use MAC address of the iphone as my unique identifier of the app. I was wondering if it changes or is it unique per device.
Thanks
回答1:
Do not use the MAC address as a replacement for the UDID. Use the Identifier For Advertisers [IDFA] or the Identifier For Vendors [IDFV] instead.
p1. The MAC address is not required to be globally unique.
p2. Even when the U/L bit in the EUI-48 or EUI-64 format identifies the address as "universal," the MAC address is not required to be globally unique. All that bit really means is that the OUI is globally registered, and the organization that it identifies is assuming responsibility for registering the individual addresses that use that OUI.
p3. Seriously, the MAC address is not globally unique. Ask anybody who works in a network interoperability laboratory. Hardware manufacturers reuse them all the time, according to policies they never discuss publicly. It is not a replacement for the UDID.
p4. The operating system is under no obligation to present the actual hardware MAC address to non-privileged applications. The current version may be doing that today, but some future version might rather suddenly and silently stop doing that. It could start returning an identical address on every device.
Do not use the MAC address as a replacement for the UDID. Use the Identifier For Advertisers [IDFA] or the Identifier For Vendors [IDFV] instead.
回答2:
UDID API is deprecated in iOS 5. To get a unique identifier, you need to use the MAC address
A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces
回答3:
There are many reason not to identifier a device.
Just create a unique identifier for the installation or allow the user to create an account. Any other method to identify the device could really cause problems.
If for example someone sells there phone, then the next user will see all the data in the app from the previous user. Since you do not identify the user but the device.
回答4:
You can simply use the UDID
Like the name said it's an Unique Device Identifier
回答5:
I would also give a go on IMEI which is suppose to be 100% unique per phone.
回答6:
MAC address is unique in the whole world - read MAC address. Err, it should be. There're ways how to change it, but it's not a task for common user, so, yes, you can use it.
People tend to use things like OpenUDID and friends.
Go to uncle Google and search for "iOS deprecated UDID" and you can have something to read for the whole night :) Or here's some summary.
来源：https://stackoverflow.com/questions/11505015/is-mac-address-of-iphone-unique-and-will-it-change