The present explanation was deliberately simplified for reasons of comprehensibility. Also, all implemented security measures and other details were omitted. If you need more information, please, read the technical details.
Taking a photo
First of all, an inquiring person (you) needs a fully Bluetooth LE -compatible mobile device with the Speciface application installed on it. This device should be equipped with a camera and have an Internet connection.
You can use this application to take a portrait photo of a nearby person, whose contact information you want to gain access to (you may need to have his/her direct consent to do so). There is another option: activate “People around”, wait a minute and pick a person from the gallery of accessible people. Anyway, in order to proceed any further this application needs an image of the person’s face. It’s used then by a face recognition algorithm to produce a short description code for this face. Such rough face codes are practically useless to identify anyone, however, they allow the application to perfectly distinguish people nearby.
Requesting data
The mentioned requirements are applied to the target person’s mobile device as well. Moreover, the target person needs to have a registered profile in the Speciface application. At last, the application’s “discoverability mode” on this device should be enabled.
So, an inquiring device uses its Bluetooth LE interface to broadcast the face code. It means that all nearby BLE-enabled devices will receive this request. Having received that, each of them can compare the received face code with the one that had been created previously during the profile registration. However, only the target person’s device detects a match. Thus, it prepares to share the information that this person marked as “publicly available” in his/her profile.

Receiving data
Now, depending on the selected discoverability mode, the target person may need to give his/her device the final permission to send this data to your device. In case of positive decision it finally connects to your device via Bluetooth LE and transmits the data.
At last, your device displays this information to you. Along with this data it shows the profile’s age (a number of days, passed from the profile creation date), which may give a certain level of confidence, that present data was truly provided by a particular person and not by anybody else around. However, to be completely sure, you may ask this person to confirm, that the displayed word is his(her) actual confirmation word.
NOTE: Several important features were put out of the scope of this description. Whether you plan to provide your own contact data or not, it’s recommended to read about them.