Fidesmo AB

Fidesmo open sources APDU-over-Bluetooth protocol - Fidesmo devices are now reachable from any smartphone

Blogginlägg   •   Nov 18, 2016 08:15 CET

Last time we discussed the future wearable cloud, where the Fidesmo vision is that some important functions of the mobile phone can be distributed to a set of wearables. In order for this to work, we need to enable non-technology driven companies to integrate technology seamlessly into their devices, and the devices need to be able to interact with one another independent of brand and phone application.

This calls for standardized or open protocols that devices can use. Today Fidesmo is publishing our open protocol for transporting secure chip commands (called APDUs) over Bluetooth Low Energy (BLE), and we are also publishing reference implementations for the client and server parts so that you can test out the protocol just with two Android phones.

This enables a wearable manufacturer to implement a device with Fidesmo functionality and make the Secure Element inside that device accessible by any application or device that implements the BLE client side of the protocol.

One possible use case is to issue public transit tickets from the public transit operator’s own application, and transfer them over BLE to your wearable, as long as the app implements this protocol. Or to issue your payment card directly from your banking app to any device that implements the protocol. By not forcing a proprietary protocol onto the devices, the number of possible combinations of devices and use cases increases exponentially.

It is also important that the protocol can be used with both passive and active devices and that it is as lightweight as possible. We believe we have found a good compromise but are of course open for feedback.

So please review our first contribution to the wearable cloud, and start to play with the code. You can find the specification and code here: We are looking forward to your feedback.