Verify the use of CryptoCell

RE: Verify the use of CryptoCell

dejans — Thu, 01 Feb 2024 10:10:39 GMT

Hi,

[quote user="NicolasK."]The small data blocks don't seem to be the causing factor for the longer duration. It seems to be the ChaCha20 encryption itself that is slower with CryptoCell. I tested the AES-CBC sample and the duration with CryptoCell is 1/5 of the time compared to Oberon.[/quote]

Thank you for this update.

Best regards,
Dejan

RE: Verify the use of CryptoCell

NicolasK. — Wed, 31 Jan 2024 08:56:36 GMT

So we did some more testing. The rom_report (found in Visual Studio Code SC memory report) did help to see if CryptoCell is being used.

The small data blocks don't seem to be the causing factor for the longer duration. It seems to be the ChaCha20 encryption itself that is slower with CryptoCell. I tested the AES-CBC sample and the duration with CryptoCell is 1/5 of the time compared to Oberon.

RE: Verify the use of CryptoCell

dejans — Mon, 29 Jan 2024 16:36:28 GMT

Hi,

[quote user=""]

Am I using CryptoCell for the en-/decryption?
How do I check this properly?

[/quote]

For checking if CryptoCell is used, you could use rom_report or tfm_rom_report and check for cc3xx_ prefixed APIs on a driver level.

[quote user=""]Why is Oberon faster?[/quote]

Oberon does not have single usage requirement (in contrast to CryptoCell hardware). This means that it does not have to wait to get a single access. Additionally, CryptoCell takes longer time for initialization if the content that is going to be encrypted is small. On larger blocks of data, CryptoCell is much faster.

Best regards,
Dejan