Imporatnt for avoid to stay on iTunes error while you restoring your iPhone , iPad , iPod who take cares about this small detail before restoring an iPhone or other apple device .
sure most of folks never mind it before crying for iTunes error 3149 ( current ) and much others. this is a policy of apple which is to signed some firmware and unsigned some else .
as exemple : is to allowed 5.1 restoring possible and stop 5.0.1 restoring .
this up commonly when a new iOS is Release they block old to work .
but they never make it without give alternative to keep your iDevices signed .usually when a new firmware get out apple allowed in a short time to hold firmware signed , by saving SHSH blobs on apple server which will use to idenfy your device while a downgrade procedure and will permit you to back on an old iOS version .
at this time even SHSH blob saving can't help to Downgarde an older firmware if you unfortinatly upgrade to a high version . since the Limera1n Exploit is fixed in the bootrom since version Bootrom 838.3 and because iOS since 5.0 includes a nonce in their SHSH hashes, downgrading newer devices (iPhone 4S, iPad 2, iPad 3, Apple TV 3G) to earlier 5.x firmwares is impossible, even with iFaith. Until a Bootrom or LLB exploit is found, it is recommended to stay on a jailbreakable firmware until such time that the latest firmware is jailbroken. . To downgrade the firmware, simply change your hosts file to map any request to an Apple server to point to Saurik's server instead, if your certificate is there. If you have the file yourself, run TinyUmbrella's TSS Server on your local machine. Note, though, that downgrades to iOS 5 or newer are currently not available.so bad that . currently only four iOS version are still signed by apple . these are below
iOS For Devices
4.1 iPhone 3G, iPhone 3GS, iPod touch 2G, iPod touch 3G
4.2.1 iPhone 3G, iPod touch 2G
5.0 Apple TV 2G, Apple TV 3
5.1 iPad, iPad 2, iPad 3, iPhone 3GS, iPhone 4, iPhone 4S, iPod touch 3G, iPod touch 4G
Download different iPhone iPad iPod iOS Here
thank to iPhone Wiki
sure most of folks never mind it before crying for iTunes error 3149 ( current ) and much others. this is a policy of apple which is to signed some firmware and unsigned some else .
as exemple : is to allowed 5.1 restoring possible and stop 5.0.1 restoring .
this up commonly when a new iOS is Release they block old to work .
but they never make it without give alternative to keep your iDevices signed .usually when a new firmware get out apple allowed in a short time to hold firmware signed , by saving SHSH blobs on apple server which will use to idenfy your device while a downgrade procedure and will permit you to back on an old iOS version .
at this time even SHSH blob saving can't help to Downgarde an older firmware if you unfortinatly upgrade to a high version . since the Limera1n Exploit is fixed in the bootrom since version Bootrom 838.3 and because iOS since 5.0 includes a nonce in their SHSH hashes, downgrading newer devices (iPhone 4S, iPad 2, iPad 3, Apple TV 3G) to earlier 5.x firmwares is impossible, even with iFaith. Until a Bootrom or LLB exploit is found, it is recommended to stay on a jailbreakable firmware until such time that the latest firmware is jailbroken. . To downgrade the firmware, simply change your hosts file to map any request to an Apple server to point to Saurik's server instead, if your certificate is there. If you have the file yourself, run TinyUmbrella's TSS Server on your local machine. Note, though, that downgrades to iOS 5 or newer are currently not available.so bad that . currently only four iOS version are still signed by apple . these are below
iOS For Devices
4.1 iPhone 3G, iPhone 3GS, iPod touch 2G, iPod touch 3G
4.2.1 iPhone 3G, iPod touch 2G
5.0 Apple TV 2G, Apple TV 3
5.1 iPad, iPad 2, iPad 3, iPhone 3GS, iPhone 4, iPhone 4S, iPod touch 3G, iPod touch 4G
Download different iPhone iPad iPod iOS Here
thank to iPhone Wiki
