On the BCM20737S, the RSA library is implemented in firmware and is a direct port of the Polar SSL library (version 1.7)
- What little we have in the way of documentation is here: /WICED-Smart-SDK/Wiced-Smart/bleapp/utils/rsa.h
- Note that our WICED Secure Over-the-Air Firmware Upgrade Application Note (SDK 2.x and TAG3 Board)/process levrages the RSA library that's onboard.
The extra RAM needed for RSA is only allocated by apps that require the RSA library.
We essentially provide a path for authentication and other security mechanisms that rely on the capability to run standard security functions (SHA1, MD5 etc.) . For instance, you may need to authenticate a user before opening/unlocking a BLE based device or authenticate a secure medical device before granting it access to an iPhone.
Additional power is only consumed during encrypt/decrypt and authentication.
Here's some additional threads on the subject:
Thank you for replying. Do you have functions for symmetric-key encryptions such as AES or others?
I'm pretty sure the answer is no as what we have leverages the Polar SSL library and is located under the /WICED-Smart-SDK/Wiced-Smart/bleapp/utils directory.