Page 45 - U4SSC Blockchain for smart sustainable cities

Case 2. Allowing young people to verify their age in Amsterdam

When personal data need to be verified, one To this end, the app is answering a question such
of the challenges is to do this in a manner that as “Are you 18 or older?” with a simple Yes or
reveals as little as possible about the individual. No. It does not need to reveal what the actual
The Claim Verification 18+ is a prototype age of the individual is, or their date of birth. This
application that enables people to prove that is known as a data minimizing authentication
they are over 18 years old, without revealing mechanism.
their name, date of birth or other information. The system was tested during 2018 and 2019;
Such an app could be used to gain access to a and based on the results, the city of Amsterdam
club or to buy alcohol. has decided to develop an app called Stadspas

The goals of this pilot project were to: (City pass) to facilitate access to city services as
a. develop a useful app; part of the “Open City” programme. 67
b. improve understanding of the user experi- The Claim Verification 18+ prototype is
ence and journey; based on the technologies developed by the
c. give people control over their personal data; DEcentralized Citizens Owned Data Ecosystem
and (DECODE) project, which is a three-year project
funded by the European Commission, involving
d. test out the capability of the DECODE tools 14 consortium members.
(which are described below).
This project has been developing tools that give
The Passport Box piloted a system for people people control of their data using “entitlements”
to prove that they are over a certain age, for attached to private data. It uses blockchain
example, over 18, without having to share their technology and cryptography to develop
full identity, date of birth, or social security software tools for managing personal data, while
number, through the use of attribute-based also investigating data governance models to
credentials. Claim Verification 18+ consists of better understand how data can be shared for
a mobile app and a passport scanner. The economic benefit.
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passport scanner is a physical box that scans The backbone of the DECODE platform is Zenroom,
the RFID in a passport and records information a “process virtual machine” that implements
about the individual. This process needs to be zero-knowledge proof authentication and
completed just once. The app then allows the attributes-based credentials. Zenroom was
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supplier, who needs the information verified, to used as the basis for all the DECODE prototype
pose a question to the individual on their phone systems.
with an accompanying QR code. The individual
can scan this code with their phone and choose
whether or not to have the app answer the
question.

U4SSC: Blockchain for smart sustainable cities 35