TinyUmbrella, the application that allows save the SHSH from your device from your Windows or Mac computer has just been updated to version 6.13.00 which allows you to save the SHSH of iOS 6.1.3 from your iOS device.
It is very important to use this tool after errors that have been in Cydia when saving the SHSH, since the APTickets that are also usually saved together with the SHSH have not been saved in Cydia automatically, but they have been saved if you have done it with TinyUmbrella, so these are the only ones that are complete (also if You have saved them with RedSn0w or iFaith, therefore the SHSH of iOS 6.X saved in Cydia automatically are useless and it is advisable to always do it with TinyUmbrella.
SHSH can be used in some cases to downgrade, so it is very important that you all save them, although they are currently not useful in new devices such as iPhone 5 or 4S (this happens because there is no hardware exploit for these devices).
You can download TinyUmbrella here:
In this version, a bug that sometimes occurred in Windows has been fixed. The author is working on rewriting TinyUmbrella from scratch, to make the app self-update without having to download it again, but it still has to be downloaded each time.
NOTE: Remember to uncheck the option "Request SHSH from Cydia”In the Settings if you get an error.
More information - Tutorial: what are SHSH and what are they for
