Publications

Calypso is an auditable data-management framework that allows decentralize sharing and life-cycle management of private data. It is describe in this paper: https://eprint.iacr.org/2018/209.pdf. We use Calypso to store private data on the blockchain. DARCs describe the access to this private data. We use it in an example game of rock-paper-scissors…

C4DT is working on bringing software from the labs to the real world. As part of this effort, we’re working on implementing use-cases for OmniLedger. OmniLedger is a novel blockchain that offers several new features. For example it works as a decentralised login service. This means that there is no…

Current access rights management systems always depend on a centralized authority that all members must trust. However, for blockchains, this is not a good solution. Blockchains are decentralized and cannot easily use centralized trust systems. We built DARCs, a group-management on steroids that allows decentralized administration and delegation of identities.…

Every week at our engineers-meeting we have a short presentation of _anything_ we found on the internet that is somewhat work-related and that we would like to share with our fellow engineers. As the team-lead, I wanted to do some short team-building exercise, and I thought about the game “The…

The C4DT Factory works using software produced by the EPFL IC labs. Our focus is on software that increases digital trust in the era of the internet. One area where we see a lack of trust is account management, which includes the following elements: self-sovereign management of the account using…

The DEDIS lab at EPFL worked on a novel blockchain system called OmniLedger. It uses Calypso to provide decentralized access control including secure storage of data on a blockchain. This combination has the following characteristics: OmniLedger builds on byzcoin, a permissioned, public blockchain which uses little energy. Contrary to other…

For a bit more than three years, DEDIS has been working on a blockchain based on the byzcoin paper. The groundwork has been laid to add client interactions, first as a number of command line interfaces, then a first web-interface, a second interface added by C4DT as a demonstrator, and…

When working on the command line, it is common to build complex commands that connect sub-tasks through the pipe. In those situations, it can be useful to have an idea of the data transferred between two connected processes. For example, what is the throughput? What about the volume of data…

Most projects need organization. There exists a bunch out there, from the post-its laying on the desk to a huge kanban spanning the whole chain of supply. With code¸I find using the same layout as the project is pretty practical: when digging deeper inside it, you get more relevant information,…

For the “Foundation of ICT and Digital Trust” course organized by C4DT, I gave a 1h-slot on distributed trust and blockchains. Here is the link to the slides: Google Doc presentation

The Center for Digital Trust is always searching for novel ways to decentralize control of users accounts so we don’t have to rely on a centralized structure that can be abused by administrators. Currently we have three kinds of services that we offer to our partners: A matrix.c4dt.org installation for…