TENACIOUS: Trustworthy sEmaNtic Aware marketplaCe for Interoperable clOUd Services

One of the most appealing characteristics of Cloud Services is represented by the possibility to compose them and create complex orchestrations according to user’s requirements. Semantic descriptions of Services’ interfaces allow for the discovery, composition and orchestration of heterogeneous Services, by increasing the interoperability thereof through matchmaking and inferencing. However, solutions leveraging Semantic enabled discovery and composition of Services suffer from a general lack of trust in the provenance of services’ interfaces descriptions: not up-to-date or incomplete representations of such interfaces can lead to erroneous compositions, or disrupt the orchestration process. Moreover, updates to the Services’ interfaces need to be catched by the Semantic representation, and all changes need to be tracked in order to reach consensus and build trust.

To address these issues, a multi layered Semantic representation of Cloud Services and Patterns will be used as the enabling technology for the discovery, composition and orchestration of Cloud Services, and it will be coupled with Blockchain technologies to build a trusted and secured Marketplace. The Marketplace will allow potential customers to access the semantic database through SPARQL queries, automatically generated on the basis of the expressed functional and nonfunctional requirements. Cloud vendors will be in charge of providing actual representations of their Services by following a shared semantic model, which will be used for services’ matchmaking and interoperability. All changes made to the semantic model, together with the creation of RDF triples representing actual compositions and Services allocations will be tracked within the blockchain. A Permissioned Blockchain will ensure that only trusted, authorized individuals will provide services’ descriptions and updates, thus concurring to building trust on data provenance and content. Smart Contract based mechanisms will be exploited to manage SLAs among customers and contracting vendors, with the marketplace responsible for the monitoring and calculation of eventual compensations.



Motivation for the project:

The project addresses Cloud services composition through semantic technologies, also applying blockchain technologies to ensure security and increase trust, with the potential to bring benefit to every domain listed in the ONTOCHAIN objectives.

Generic use case description:

An expert programmer affiliated to known companies in need of specific functionalities, accesses the Marketplace and discovers the services best suiting her needs, getting support in the composition and orchestration of the selected solutions.

Essential functionalities:

Access to a secure and trustable Marketplace where semantically described Cloud Services can be Researched, Discovered, and Composed, according to the specific requirements needed.
Storage of the composed solution in RDF format within the Blockchain, to ensure the compliance to a proposed contract.

How these functionalities can be integrated within the software ecosystem:

The proposed semantic description of Cloud Services will be adapted to existing definitions already in use within the Ontochain system, and the support to Pattern representation will foster the overall interoperability of the framework.

Gap being addressed:

There is a general lack of trust in existing services’ descriptions and directories, and public repositories and aggregators of such services are currently missing. Frequent variations in exposed interfaces and lack of proper descriptions hinder interoperability and portability of applications.

Expected benefits achieved with the novel technology building blocks:

Increment the willingness to purchase cloud services leveraging the trust established by using blockchain; increment the discoverability of cloud providers, increasing the competitiveness and reducing costs; drastically reduce the legal dispute on the SLAs, between cloud providers and customers.

Potential demonstration scenario:

The potential demonstration scenario is represented by the iExec platform, which already provides a description of offered Services that can be extended and made interoperable through the proposed semantic approach, also taking in consideration the possibility to widen the list of offered services.






Antonio Esposito

Antonio Esposito is currently Assistant Professor at the Department of Engineering of the University of Campania "Luigi Vanvitelli".


Emanuele Bellini

Emanuele Bellini is currently Assistant Professor at Mathematics and Physics Dept. on Concurrent and Parallel Programming at University of Campania “Vanvitelli”(IT) and Research Fellow at Khalifa University, Abu Dhabi (UAE).


Beniamino Di Martino

Prof. Beniamino Di Martino is Full Professor at the University of Campania (Italy) and Adjunct Professor at Asia University (Taiwan).


Ernesto Damiani

Prof. Ernesto Damiani is Full Professor at Università degli Studi di Milano, Director of Center for Cyber Physical Systems (C2PS) within the Khalifa University, leader of the Big Data area at Etisalat British Telecom Innovation Center, and President of the Consortium of Italian Computer Science Universities (CINI).


Stelvio Cimato

Prof. Stelvio Cimato PhD is Associate Professor at the Computer Science Department of the Università degli Studi di Milano.





CINI is a consortium of 39 Italian universities that carry out research in Computer Science/Computer Engineering, deliver MS/PhD degrees, and that are publicly funded.