Data protection in external SRAM interfaced with STM32F4 series controller

[NM.1]

Hi All,

I have an application running on STM32F439 based controller board. And I am planning to use external SRAM.

I wanted to know, how we can protect the data in external SRAM ?

Or any suggestion on using external SRAM with assumption of security.

Thanks!!

[waclawek.jan]

External SRAM has exposed all data and address pins, so if the adversary has physical access, there's no way to prevent observing or actively reading out data.

But security is a wide topic. You can for example prevent physical access by encapsulation+tamperproofing, then the question reduces to securing the code. Or you can encrypt/decrypt data, but then it's upon you to judge whether encrypted data may leak relevant information and/or how to tamper-proof them.

JW

[Tesla DeLorean]

Consider different parts with enough internal memory to do the job. Or just put data in SDRAM ​the user can see anyway, like a frame buffer, or data as it comes over the network.

[NM.1]

Thanks @Community member​ it was a great insight.

[NM.1]

Thanks @Community member​ for the input.

Its a great help.