Is fast 4096 bit asymmetric encryption in the pipeline?

[meetandyhere]

We are using the NRF52840 as a basis for BLE-based secure IoT network. I know that the Crypto library enables hardware-accelerated encryption/decryption. However, as far as I understand, the maximum key length is 512 bits?

I wanted to ask if Nordic as a chip/hardware in the pipeline/already available that can enable fast hardware-accelerated 4096 bit key asymmetric encryption/decryption for a 500 KB payload? Typically we would need the encryption/decryption to finish in under 1 second.

Thanks in advance for any information!

Regards

Andy

[Krzysztof Zaraska]

Errr... you don't encrypt the payload with asymmetric cypher. You encrypt the payload with a symmetric cypher like AES using a random key, and then use asymmetric cypher to encrypt the AES key. Also, 4096-bit key size suggests you are using RSA. Why not switch to ECC? Both faster and smaller key size for the same security.

[endnode]

Yes, there are SW implementations which probably fits into flash and RAM and it will work. However performance will be poor and if you plan to do more than few such RSA operations per one transaction then it can take seconds and minutes...

Google some references (which should show you that changing from RSA to ECC or better some standard ECC+AES scheme on your backend might be the only option;) like:

• crypto.stackexchange.com/.../rsa-signature-verification-implementation-on-cortex-m0
• csrc.nist.gov/.../session7-vincent.pdf