This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 13 December 2021 |
| Upload Date | 03 December 2021 |
| File Name | iPhone_4.0_64bit_15.2_19C56_Restore.ipsw |
| File Size | 5.03 GB |
| SHA256sum | 10473f5841847fe03e4649bb71970c4a2a395eed081590cab90d2512c6ee5108 |
| MD5sum | 510af7dd823bc0d7665aee8fe6ba94e7 |
| SHA1sum | 123d259fc25fd775576acaa83747bf5311ca334e |
| Identifier | iPhone8,4 |
cd ~/Downloads.idevicerestore -e iPhone_4.0_64bit_15.2_19C56_Restore.ipsw and press Enter.