This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 08 April 2015 |
| Upload Date | 04 April 2015 |
| File Name | iPhone4,1_8.3_12F70_Restore.ipsw |
| File Size | 1.44 GB |
| SHA256sum | 0c71642bcb2e23ea7be7205b489f7dc0484b439df90919a4467b3d0c546b74aa |
| MD5sum | 51217942e98f854784f324a1833baa3b |
| SHA1sum | 2b1b3e1670c65d142aaecbe91b30f72c5d459265 |
| Identifier | iPhone4,1 |
cd ~/Downloads.idevicerestore -e iPhone4,1_8.3_12F70_Restore.ipsw and press Enter.