This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 03 October 2017 |
| Upload Date | 28 September 2017 |
| File Name | iPhone_4.0_64bit_11.0.2_15A421_Restore.ipsw |
| File Size | 2.43 GB |
| SHA256sum | d1b3681f28a974e86a10d54786c3d46c8f44b2ab98a4042f10f432d093649644 |
| MD5sum | f85931deec288e4f07d04e19d455464b |
| SHA1sum | 555c00cd8c150a87becbfca114c95b5c81999c84 |
| Identifier | iPhone8,4 |
cd ~/Downloads.idevicerestore -e iPhone_4.0_64bit_11.0.2_15A421_Restore.ipsw and press Enter.