Program iFaith launched by iH8sn0w a few months ago turns out to be extremely useful not only for saving SHSHs but also for discovering new information about how Apple builds the entire ecosystem of SHSHs. It seems that Apple uses 2 types of SHSHs to restore iDevices, more precisely a SHSH for installing iOS in partner factories and a separate SHSH for restoring from iTunes. This was discovered by iH8sn0w after some people told him that using a SHSH saved with iFaith for a recently purchased product that they had not restored, they ended up in a DFU loop after trying to use that SHSH with iTunes.
Basically, the SHSH used to install iOS in Apple factories is not compatible with iTunes and its saving using iFaith does not allow its use in the case of a restore. If there is a SHSH for the factory and it can be saved then there is a chance that the Dev Team or other skilled hackers will find a method to make it "compatible" with iTunes and avoid the restrictions that Apple wants to impose in the future. However, for now we know that there are 2 types of SHSHs and nothing more, it remains to be seen how the situation will evolve in the future.
