Chip-off acquisition is a highly advanced, destructive extraction technique that requires attaching wire leads to the PCB contacts or physically removing (desoldering) the phone's flash memory chip. Chip-off is considered more difficult compared to JTAG; however, the amount of information acquired via chip-off acquisition is similar to the amount of data acquired by JTAGging the device. Since most smartphones use standard eMMC flash modules, the process is standardized and typically presents no surprises to the examiner.
When imaging computer hard drives, one normally attempts to go as low level as possible. In the world of mobile forensic, the lowest-level access is not always the best. While reading the chips directly produces a complete raw dump of the memory chips, the investigator may be faced with an encrypted partition with no decryption keys stored anywhere around. In the case of Apple devices, many Samsung phones, and other devices (for example, the Android 5 Nexus line...