SID

= Security/Chip ID =

The Allwinner A-series of SoC's (A10, A10s, A12, A13, A20 and A31) feature a series of efuses used as a unique Chip ID. Other potential uses for these efuses are:
 * MAC address
 * Encryption Key
 * Entropy seed
 * Product serial number

These 128 bits are in theory programmable, but most likely require a certain programming voltage (efuse_vddq) applied to pin T9 (on A10/A20) that is normally tied to GND. Feeding said pin with anything but GND will in practise be hard, since the BGA pin will most likely tied directly to GND.

While these bits tend to be programmed reasonable for a lot of SoC's, there have been SoC's in the wild (mele A1000 so far) that has these efuses all set to 0!