GID Key

The GID-key (device group ID key) is the AES 256-bit key shared by all devices with the same application processor. This key differs between each SoC. (i.e. The S5L8900 has a different key from the S5L8930.)

It was used to generate Key 0x837.

In iOS 3.0GM/3.0, a pseudo GID Key was used. This allowed getting firmware decryption keys for these firmwares only without the device and with tools such as GitKeys or OpenSSL.

Attack
It would be great to perform some sort of side channel attack on this to extract it:


 * Quo Vadis Labs
 * Fault attacks on secure chips: from glitch to flash (Part 1)
 * Side-channel attacks: new directions and horizons (Part 2)
 * Research project: developing new technology for efficient side-channel analysis