Self Crypto

From PS3Wiki

Here is a small summary on how the self cryptography works.

Basically here are the steps being involved by the loaders:

Loaders all have a static key and iv called respectively erk and riv, those are keys for the first decryption step which are used to decrypt the very first 0x40 bytes of the self's metadata using AES256CBC

Then the result is used as a key and iv to decrypt the rest of the metadata using AES128CTR, finally the decrypted metadata contains the keys and iv for each data sections which are still decrypted through AES128CTR. This security model is based on the fact that the first 0x40 bytes of the self's metadata once decrypted by the static AES256CBC key in the loader should never be the same from one binary to the other. The same goes for any other value used as an AES128CTR key or iv.

Loaders are also involved with inflating the binaries using zlib.

The self authenticity is based on other independent steps, HMAC-SHA1 and ECDSA for the actual signature.