Gazelle & NRF 52840

[Samuel01]

I am trying to evaluate the NRF 52840 using the Gazell protocol.

I need some secured link between 2 devices with a low latency, and authentified (so no one can replace one of the devices, inject etc). But I also need some communication in both ways so with ack payload. The encryption (hide the data from a sniffer) is not mandatory, while it doesn't allow an attacker to do injection or spoofing etc.

I see that the Gazell protocol can encrypt, which I don't need, but I am  not sure if the data unencrypted is authentified when a device and a host are paired and comunicating using unencrypted data ?

If the gazell protocol doesn't match, do you have any other secured (encryption is not mandatory) link that could be interesting ?

Thanks for the clarification !

[Samuel01]

If you have a look at the gzp.h, you will see for the host the functions 

gzp_crypt_user_data_received and 

gzp_crypt_user_data_read. 

And for the device the function 

gzp_crypt_data_send.

But there is no send function for the host, or attach_payload function.

[Kenneth]

Sorry, you are right. I was under the impression it was, but it's been a while since I worked on Gazell so my memory proved me wrong.

The GZP API doesn't provide a specific high-level function for host-to-device encrypted data because it uses the underlying Gazell ACK mechanism. For encrypted host-to-device communication, you need to manually encrypt the ACK payload data before calling nrf_gzll_add_packet_to_tx_fifo() on the host. So maybe that can help.

Kenneth