Hands-on Trainings

Delivered by the Factory, the main goal of the hands-on trainings is for partners to better understand and integrate the libraries offered by the C4DT.


When doing statistical analysis of data between multiple stakeholders, it is sometimes difficult to get access to the data itself that should be included in the data. This can be because of legislation, such as GDPR, privacy concerns, or for other reasons. Drynx solves this problem by keeping the data encrypted at all times, in particular when performing computation. Only the final result is decrypted.

This procedure is called homomorphic encryption, and up to recently, it has been synonymous with slow calculations. Drynx uses a novel approach that is much faster. It prevents malicious stakeholders to modify the statistics by manipulating the raw data. It also proves that all operations have been done correctly.

Drynx is currently evaluated using medical data, where the privacy constraints are very high. C4DT is preparing a demonstrator that shows how it can be applied to data used in the re-insurance business where different stakeholders cannot share data in plain text because of legal reasons.

Calypso & DARCs

As soon as different data owners who don’t trust each other want to share data, a blockchain can bring the necessary trust between the different partners. However, first generation blockchains couldn’t handle sensitive data, as every node has the full view of all data. The OmniLedger / Calypso blockchain from Prof. Bryan Ford’s lab at EPFL enables data owners to share their data in an encrypted way and to maintain control over who has access to which data. Using a blockchain means that there is no single point of failure which would allow to access the documents in a fraudulent manner.

Another challenge when sharing data is who has access to which data. In practice this means who manages the access rights to your data. At all times you will be able to trace who accessed the data. As the access to your data is based on blockchain technology, the audit trail is immutable, so that misbehaving users can be held accountable.

The challenge with decryption is that one compromised keypair can lead to the decryption of all stored data. This is why Calypso uses multiple decentralized keypairs to secure the data. An attacker must get access to all keypairs before he can fraudulently decrypt the data. At C4DT we run a public installation of the OmniLedger blockchain and use it for access control to our website and chat system.

Related news

Apr 22, 2021Press reviews
The certificate linked to the virus will not be available before June in Switzerland. Until then, here are twelve answers linked to questions of security, data and accessibility concerning what some call the "Immunity Passport". In particular, Jean-Pierre Hubaux, C4DT Academic Director, provides insights on the questions linked to data.

Apr 12, 2021Press reviews
RTS Debate between Anne-Marie Kermarrec, computer scientist and C4DT affiliated professor at EPFL, author of "Numérique, compte avec les femmes" (Odile Jacob, 2021), Isabelle Collet, professor of education at the University of Geneva, author of "Les Oubliés du numérique" (Le Passeur, 2019), Brigitte Manz-Brunner, responsible for the French-speaking part of Switzerland for the campaign "Tout feu tout flamme - Pour plus de femmes dans l’informatique", and Marina Pantazis, developer at Calitho SA.

Mar 25, 2021Press reviews
Digital activities represent around 4-5% of CO2 emissions, estimate several studies. And cryptocurrencies, like Bitcoin, are amongst the most energy consuming activities: far ahead of streaming and email exchanges. The podcast "Le Point J" tries to understand why.

Mar 21, 2021Press reviews
Take a look at the RTS documentary on the impacts of deepfakes featuring an interview from C4DT affiliated professor Touradj Ebrahimi.

Mar 15, 2021News
The ease of creating fake virtual identities plays an important role in shaping the way information—and misinformation—circulates online. Social media platforms are increasingly prominent in shaping public debates, and the tension between online anonymity and accountability is a source of growing societal risks. This article outlines one approach to resolving this tension, with “pseudonym parties” that focus on proof of personhood rather than identity. Pseudonym parties are a low-tech approach to important digital challenges, linking online activity to anonymous digital tokens that are obtained by being physically present at an appointed time and place.

Next courses

Jun 7, 2021 → Jun 11, 2021C4DT courses
Current digital trends and innovation, including artificial intelligence, cybersecurity, data privacy, blockchain and digital trust, are rapidly changing and disrupting the way donors, employees, and beneficiaries interact with each other. Technology can be a powerful tool for philanthropic and non-profit organizations, accelerating their digital transformation through automating and streamlining business processes, using digital platforms, and leveraging data and analytics in new ways that enhance their efficiency and social impact.

No upcoming courses