  In several domains it is crucial to store and manipulate data whose origin
needs to be completely traceable to guarantee the consistency, trustworthiness
and reliability on the data itself typically for ethical and legal reasons. It
is also important to guarantee that such properties are also carried further
when such data is composed and processed into new data. In this article we
present the main requirements and theorethical problems that arise by the
design of a system supporting data with such capabilities. We present an
architecture for implementing a system as well as a prototype developed in
Pharo.
