Attinyx4 and MC6HC905xx Family

Hello, I am new to glitching and side attacks. Looking to play around with ATTINY44A and the Freescale MC6HC905xx.

Has anyone already done this?

Is the idea to obtain your own blank target MCU, write your own code on the MCU, upload it, play around with the glitching and see what you can do? Then hit your real target on the lessons learned from working on yours. I guess that is more Whitebox, as opposed to just ‘attacking’ the chip? All I really want to do is see if I can get around the fuse bits to read the EEPROM.

Reading the datasheet on the MC6HC905, there is this monitor mode that can be triggered, looks like a pain in the butt to trigger. However, the developer can disable this monitor mode in the fuse bits. Even if they have it enabled, there are 8 bytes the serial port will look for if the monitor mode is triggered. These are also stored in what I would assume to be a secure area on the EEPROM.

After reading through the datasheet, I still don’t know how to read the fuse bits. heh It looks like I need a HC08 programmer… And their dev environment (CodeWarrior).

I am assuming the ATTINY44 will be easy…??