Firmware Authentication and RSA

Yongwei Wu

Other Parts Discussed in Thread: CC2541

We are trying to implement a firmware update feature on CC2541. According to our security team's requirements, RSA and SHA-2 should be used to verify the integrity and authenticity of the firmware image.

I noticed the discussion in this thread: http://e2e.ti.com/support/wireless_connectivity/f/538/t/191961.aspx. I do not think using AES is good, since we must assume people can always read the firmware content in the flash in some way. Therefore, asymmetric cryptography should be used.

Does anybody have experience in implementing RSA in CC2541? Or does anybody have a secure alternative?

Thanks in advance.

over 11 years ago

0 Willis1 over 11 years ago

TI__Genius 17975 points

Unfortunately we do not have any sample applications that implement RSA on CC254x.

0 Dhaval V over 11 years ago in reply to Willis1

Genius 4470 points

Hi Willis1,

Is there any library available for RSA?

Is CC2541 capable enough to satisfy the processing requirement of RSA?

Thanks,

Dhaval

0 Yongwei Wu over 11 years ago in reply to Dhaval V

Intellectual 260 points

I have had some searches and experiments. Doing 1024-bit RSA signature verification seems feasible. When using public exponent 3, verification took 1.x seconds; when using public exponent 65537, verification took 4.x seconds. I guess decryption/signing is out of the question.

0 Yongwei Wu over 11 years ago in reply to Willis1

Intellectual 260 points

Hi Willis,

Can TI provide some libraries for big-number multiplication/division? That is the basis for RSA, and will be useful for optimizing both the performance and size of the RSA code.

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Firmware Authentication and RSA