IFaith

iFaith is an open source SHSH dumper for the Windows family of operating systems written by iH8sn0w. It works on all devices that are susceptible to the limera1n exploit (all devices before the iPad 2). This is useful if you receive a device with old firmware on it that you want to be able to restore. Even if Apple doesn't sign that firmware anymore, you can backup the SHSH data directly from the device, so that you can install the firmware later again to avoid upgrading the firmware.

Credits

 * iH8sn0w author
 * geohot for limera1n exploit