This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 13 December 2017 |
| Upload Date | 10 December 2017 |
| File Name | iPhone_4.0_64bit_11.2.1_15C153_Restore.ipsw |
| File Size | 2.43 GB |
| SHA256sum | abe2df1486b1e3f1480d6ba1029771a48665d4454e788a0d6abb8cd580e164be |
| MD5sum | 65cc098c56bd4ebc9aeb518f74d9b071 |
| SHA1sum | 85124b66bb039b0740d7c8b61257abf1c1d07319 |
| Identifier | iPhone6,2 |
cd ~/Downloads.idevicerestore -e iPhone_4.0_64bit_11.2.1_15C153_Restore.ipsw and press Enter.