It’s a good habit to get into to save your SHSH blobs when you are going to upgrade the firmware on your iOS device or jailbreak it. The popular SHSH saving tool, TinyUmbrella has now been updated to provide support for iOS 6.1.2 but, if you don’t want to use this, there are other ways to do it.
Here are 3 other methods that don’t require the use of TinyUmbrella :
When you jailbreak your device Cydia will automatically save and store your SHSH blobs on their server. There have been a couple of reports from people who say this hasn’t happened so you can use one of these other methods.
This is another highly popular method for saving SHSH blobs and it’s available on Cydia for free. To use it, simply install it from Cydia, then open it, select Firmware choose the latest iOS version and save it. Your SHSH blobs will be saved, you can then select Manage and iSHSHit will email your blobs to you for future use.
This is desktop rather than device software and it was developed by iH8sn0w. You can download it from here. Once downloaded, extract to your desktop, connect your iOS device to your computer and then select Save Available SHSH/Cache on Server. Select Yes when you are asked about connecting to the Cydia or iFaith server. You will now see a prompt to Fetch and Submit SHSH blobs for your firmware, select Yes. iFaith will now complete the procedure and will send your blobs to the server.