What Are iPhone SHSH Blobs

For the user who is interested in jailbreaking an iPhone for the first time, some terms in the procedure might be new. The common advice before jailbreaking any device is to perform a backup of your data, but when upgrading to iOS 5 there’s a particular request to save your iPhone SHSH Blobs. For the user who is new to the world of jailbreaking, this is the kind of term that will get him to quit before even learning the jailbreak tool will do everything by itself and will not require any expert hacking skills.

SHSH blobs are a signature of a firmware image needed in case of a specific iOS version restoration. Apple generates this signature by using the hash of the firmware and the device’s hardware keys. The company only releases this signature for the available iOS version, making a restore to a previous firmware impossible. This is why it is recommended you save SHSH blobs before upgrading to a new iOS and are planning a jailbreak.

SHSH blobs are needed if you plan to restore or upgrade iOS on any of the following Apple devices: iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5, iPod touch 3G, iPad, iPad 2, iPod touch 4G, apple TV 2G and newer devices.

There are several apps designed to help you save iPhone SHSH blobs, but Redsn0w’s Cydia seems to be the least hassle-free of the options available (also see how to save SHSH blobs using TinyUmbrella). The Cydia app will be installed on your iPhone and will save any available SHSH blobs by default every time you launch the app. The data is stored on Cydia’s servers, maintained by saurik aka Jay Freeman, the creator of Cydia, WinterBoard and Mobile Substrate and a member of the iPhone Dev Team.

When saved, your SHSH blobs can be found in a folder on your computer called .shsh. You can use TinyUmbrella if your device isn’t jailbroken to see your SHSH blobs available for your device, which are retrieved from Cydia servers.

Restoring an older iOS version using SHSH blobs is a different process varying in accordance to your device’s firmware version. For instance, to restore your iPhone to iOs 5 you will have to download the SHSH blobs to your computer, add them into the firmware and restore from that. There is an extensive tutorial on that available in the designated section of the iJailbreakiPhone5s website.