Backup iPhone 4 Activation Using SAM Module after IMEI Factory Unlock

Many iPhone 4 users are buying service from Negri Electronics,  CutYourSim or SuperPaddy that officially unlocks iPhone 4 via iTunes on any baseband without jailbreaking it. Just pass your IMEI number to them, and they will do the rest with the turnaround time of 1 to 5 days.
In other words, it is similar to factory unlocked iPhone where you can update your device to the newest version without worrying about waiting for an unauthorized unlocks to be released. They’re not using a hack but using actual access to the Apple database which is why unlock happens through iTunes. That’s said! But what if Apple revokes this unlock upon restore? You will surely lose your unlock. Well! Before Apple cracks upon you, do the following steps as soon as you get first confirmation of unlock from any of the service you used to avoid the relock risk after restore. This can be done using SAM (Subscriber Artificial Module) which basically backs-up your activation record in an encrypted format to a server.
Step 1: Jailbreak your iPhone 4 iOS 4.3.1 using redsn0w, PwnageTool 4.3 or Sn0wbreeze 2.5.1 tool.
Step 2: launch ‘Cydia’ on your jailbroken iPhone 4 springboard.
Step 3: Select ‘Manage’ tab at the bottom of your iPhone screen and then select ‘Sources’.
Step 4: Select ‘Edit’ and then select ‘Add’. Now enter a URL source. Type “http://repo.bingner.com” and select on ‘Add Source’. Once Cydia adds the source, click on ‘Return to Cydia’ button.

Step 5: Once the installation is completed. Search for ‘Binger’ in Cydia and choose SAM from the list of packages and install it.

Step 6: Choose SAMPrefs from the lists of packages and install it.

Step 7: Once installation has completed press the large Restart SpringBoard button.

Step 8: Launch SAM from your SpringBoard and Navigate to Utilities -> De-Activate iPhone.

Step 9: Now, connect your iPhone to iTunes and just let it activate with the new certs this time arriving to your device allowing any-sim-usage. Done!
Note: If you are hacktivated, follow the instructions above to install SAM and launch it, then you just do a Revert Lockdownd to Stock instead of De-Activate iPhone. Now connect your iPhone to iTunes and you’re done. (Thanks Nadeem)
Alternatively, as suggested by SAM developer – Sbinger, you can navigate to Utilities and select Backup Activation. Wait till you get a notification message “Backup Report Success”. This will save the auth token (just like SHSH blobs) to avoid the relock risk after restore. It just prevents you from the lock status verification on Apple’s servers. Any backed up Activations are good for only 3 years, since that is the validity time of the signatures.
In case you want to update to latest iOS firmware after unlocking your device from the services listed above, make sure that the firmware can be jailbroken. Once verified, you can then proceed with the steps listed below:
Step 1: Launch iTunes and follow the normal firmware restore process.
Step 2: After iTunes sent the restart request to iPhone, immediately disconnect it from USB.
Step 3: After reboot you will notice a message “Emergency calls only – Connect to iTunes”. Don’t allow iTunes to perform the Activation. You will loose unlock forever and you will have to go through unlock process again.
Step 4: Put your iPhone in DFU mode. Don’t ask me how to do it!
Step 5: Jailbreak your iPhone with redsn0w and don;t forget to include Hacktivation bundle.
Step 6: Your iPhone will boot with no “Connect to iTunes” screen.
Step 7: Use “Restore Actvation” from SAMPref. Done!