**Acknowledgements**

This work was performed with the financial support of the ELKARTEK 2018 (CyberPrest project, KK-2018/00076) research program from the Basque

### *Computer Security Threats*

Government. At the same time, this content is the product of a joint effort of a group of people belonging to the Tecnalia Blockchain and Cybersecurity Research Group and it is the result of our experiences in researching, developing and applying blockchain to different sectors. We want to thank the community of hardworking developers involved in foundations and technologies like Hyperledger or Ethereum, among others, allowing us to collaboratively improve and develop new blockchain-based solutions to reach a better world.
