IBSS

A stripped down version of iBoot, missing things such as interacting with the /|filesystem. Can be uploaded via DFU to bootstrap iBEC during a DFU Mode restore.

Use of the iBSS: Your iBSS and iBEC is used to sign the firmware before uploading it to the ROM. This was a new layer of security (certificates) Apple had added to try stop Jailbreaker's.