D3.2 – UI Prototypes v2 and HCI Patterns

Contributing Partners


Executive Summary

CREDENTIAL is an EU-funded Horizon 2020 project that involves developing, testing and presenting cloud-based services for storing, managing and sharing digital identity information and personal data with a higher level of security than existing technology.
The CREDENTIAL Wallet is the central component of the tools and components developed within the project. It offers a set of security and application services providing, among others, authentication and authorization mechanisms combined with novel cryptographic technologies like proxy-re-encryption and malleable signatures.
In order to demonstrate the CREDENTIAL Wallet solution, there must be end-user applications providing access to its functions and the data stored. These applications have to be equipped with user interfaces (UIs). For the demonstration of the Wallet, the project defines pilot use cases of which some rely on a general smartphone app for Wallet access and one pilot in eHealth relies on specific apps for the Patient and the Doctor, respectively. Besides the pilot-specific user interfaces, the project has included research and development on user interfaces for the authentication and authorization services of the Wallet. The project has also included a tentative and comprehensive UI design for a fully-fledged smartphone app encompassing many aspects of what a “real” app would look like. This report demonstrates the final user interface prototypes (the version 2, “UI V2”) for the generic CREDENTIAL Wallet app. These prototypes go beyond what is implemented in the project pilots.
The present report makes an extensive account of the mockup app. Many of the around 100 UI pages are shown in relation to workflow series of UIs to ease comprehension. Moreover, as the V2 as well as the V1 UI have been the base for experimentation on user aspects of authentication and authorization, a summary of the many studies conducted are given, both in the form of an overview table and in the form of more detailed accounts of purpose, method, and results. The UI V2 has also been used to make a detailed evaluation from an accessibility point of view pursuant to EU Directive 2016/2102. Albeit some criteria for accessibility are depending on implanted functionality, the evaluation of the mock-sups gives a clear guidance for future developers of Wallet applications for smartphones.
In order to show the possibility in variation of app design for specific cases, a brief account of the project’s eHealth apps is given as well as sketches for UIs for a Wallet application running on a device with a computer-sized screen. The eHealth apps demonstrate that user groups can be reached via specific apps solving a specific problem. Likewise, the computer application demonstrates that if extensive data or file handling is an integral part of some users’ use of digital identity services, this can be included within a Wallet offer.
Furthermore, this deliverable generalisesfrom the UI V2 by outlining HCI design patterns for Cloud Identity Wallet apps. As the results for tested solutions there are baseline data for user experience and user comprehension, these patterns can be implemented or elaborated upon by future UI designers for apps connecting to the CREDENTIAL Wallet or to other similar technical solutions.
The report is concluded by a short discussion on the new vistas that can be imagined now when the main HCI work in the project is coming to a close. The perspectives constitute a continuation of the work on UIs and on HCI design patterns, being projections of work that can be commenced based on the foundations laid during the project. The discussion envisioning work beyond the CREDENTIAL project concerning user-centred functionality in relation to interaction techniques, assistive requirements in IdP apps, tutorials, data access logs, portability of user data from one Wallet provider to another, as well as differentiation of apps for Wallet account access designing for specific domains and needs.