Encryption in nrf52840, hardware or software?

RE: Encryption in nrf52840, hardware or software?

Amanda Hsieh — Tue, 20 Feb 2024 17:52:28 GMT

[quote user="BlueLogic"]is literally a hardware computation core separate from the CPU. Is the correct?[/quote]

Yes.

[quote user="BlueLogic"]If so, then if all the encryption/decryption tasks are done through this computation core[/quote]

Not all, only the encryption/decryption are supported by the AES.

[quote user="BlueLogic"]Could you please tell if these examples use ECB peripheral?[/quote]

Those examples demonstrate the encryption and decryption of a sample plaintext without using ECB.

[quote user="BlueLogic"]If not, how they can perform chrytographic task while being detached from the radio?[/quote]

See
Encrypting packets on-the-fly in radio transmit mode

Decrypting packets on-the-fly in rado receive mode

Just note that ECB peripheral can only be accessed through the Softdevice controller API if you use BLE: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/softdevice_controller/doc/api.html#c.sdc_soc_ecb_block_encrypt

-Amanda H.

RE: Encryption in nrf52840, hardware or software?

Omid — Mon, 19 Feb 2024 21:33:54 GMT

Thanks for the answer, but I feel like I do not receive the answer to my questions completely. Could you answer to the following original questions of mine?

[quote userid="127459" url="~/f/nordic-q-a/108380/encryption-in-nrf52840-hardware-or-software"]is literally a hardware computation core separate from the CPU. Is the correct?[/quote]

[quote userid="127459" url="~/f/nordic-q-a/108380/encryption-in-nrf52840-hardware-or-software"]If so, then if all the encryption/decryption tasks are done through this computation core[/quote]

[quote userid="127459" url="~/f/nordic-q-a/108380/encryption-in-nrf52840-hardware-or-software"]Could you please tell if these examples use ECB peripheral?[/quote]

[quote userid="127459" url="~/f/nordic-q-a/108380/encryption-in-nrf52840-hardware-or-software"]If not, how they can perform chrytographic task while being detached from the radio?[/quote]

RE: Encryption in nrf52840, hardware or software?

Amanda Hsieh — Mon, 19 Feb 2024 20:09:34 GMT

Hi,

[quote user=""]what here is meant by "AES-Core" is literally a hardware computation core separate from the CPU. Is the correct?[/quote]

The AES-Core means the General-purpose AES engine in the CRYPTOCELL — ARM TrustZone CryptoCell 310.

[quote user=""]If so, then if all the encryption/decryption tasks are done through this computation core and using the easyDMA?[/quote]

The CCM and ECB implement an EasyDMA mechanism for reading and writing to the Data RAM.

[quote user=""]Is there any encryption/decryption done in software using the CPU instead of using the AES core?

If there is also the cpu-based cryptography then how does that compare in terms of energy consumption and computation speed with respect to the AES-based chryptography? [/quote]

There is no sample such as your requirement, but I think you could implement by yourself.

[quote user=""]Could you please tell if these examples use ECB peripheral? If not, how they can perform chrytographic task while being detached from the radio?[/quote]

Example usage of ECB peripheral:
1) https://github.com/nrfconnect/sdk-zephyr/blob/main/subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/ecb.c
2) https://github.com/nrfconnect/sdk-zephyr/blob/main/drivers/crypto/crypto_nrf_ecb.c

Regards,
Amanda H.