AES encryption experience

[uri danziger]

Hi,

I would like to ask if someone has experience using the AES. I n eed to be absolutely sure that the user SW can use the AES HW block for own custom usage. If yes, Are there any limitations (ie shared resource with the radio etc)?

Thanks, Uri

[endnode]

Hi Uri,

Yes, AES ECB encryption processor on nRF51x22 works as advertised. You can see the API reference here: developer.nordicsemi.com/.../a00756.html. First obvious limitation is that only this one mode is supported (so no decryption for instance). Second is priority management: Soft Device has always priority so in case that some extensive radio action or even worse encryption for standard BLE layers are needed your API call will wait for return. I have no performance data and I guess you will need to evaluate this yourself...

Cheers Jan

[endnode]

Well cannot judge the referred post but it woks well in my application. You shouldn't need anything else then calling sd_ecb_block_encrypt(...) function (forget any nrf_ecb_... functions, these are really blocked by Soft Device when it is enabled) at it never hardfaults in our tests or production. Regarding AES encryption and decryption there is probably slight misunderstanding how these crypto primitives work. Please go through following two threads and comment when you feel they are misleading or incorrect: nrf_ecb_crypt and how to decrypt AES-ECB-Nopadding data?.

Cheers Jan