Security in ATMEL MCUs

[swamytk]

Dear Friends,

I am doing a project in ATMEL ATmega16L. I want to protect my program stored in Flash and EEPROM. Protection here means no body should be able to read or write my embedded appliance.

The ATmega16L provides the following security feature.
1. BLB01 / BLB02 / BLB11 / BLB12 - prohibits using SPM and LPM instruction in "In System Programming mode".
2. LB1 / LB2 - prohibits reading and writing Flash and EEPROM in parallel and serial programming mode.

But in spite of setting all these bits, using "Erase chip" command in serial/parallel programming I am able to override all these protection level and able to have complete control over the MCU's Flash and EEPROM area. There is a security flaw of over writing my application with some other application and trapping my inputs for the application.

Can anybody suggest me better level protection for the appliance, so that once written and locked the firmwire of mine, there should not be any chance of reading or writing chip further? I am in urgent need of this security. Any help in this regard is well appreciated.

Thanking in advance,
TKSwamy

 

[kinjalgp]

That is not a security flaw. After Erasing the device, there is nothing left in the FLASH ROM OR EEPROM. It will be blank (0xFF). So even if the user reads the memory, he won't gain anything.