BLE broadcast with digital signature or encryption (asymmetric)

[MLai]

Hi all,

I am wonder is there any way to broadcast data using asymmetric encryption algo or digital signature? As I want to encrypt my data using a key and other device to decrypt my data using another key. I had used aes and hmac for this step before, but as they are using symmetric key, they can't solve my problem anymore. Thanks a lot.

Best regards,

MLai

[Amanda Hsieh]

Hi MLai, 

I understand the question. But we do not provide support for any asynchronous signature algorithm shorter than 256 bit. So you would have to find something on your own then (not sure it is possible to get decent security though, there is probably a reason nothing shorter than 256 is used)

-Amanda H.

[MLai]

May I know is there any algorithm that is 256 bit? And would like to know if I can use ECDSA

[Amanda Hsieh]

See ECDSA - Elliptic Curve Digital Signature Algorithm doc. 

-Amanda H.

[MLai]

Thanks. I think I am going to use ble 5.0 to broadcast the longer packet, is there any thing to start with, any example for ble 5.0 beacon broadcast? I am using nrf 52840 and softdevice s140 v6.1.1

[Amanda Hsieh]

Check out Beacon Transmitter Sample Application.

-Amanda H.