Decentralized Authorization for Encrypted Data Streams



The moment we upload our data into the Internet, we give the ownership of our data. Applications trade with user data without their consent. There is no need to give up data ownership, to use innovative services!


Few cooperations control majority of data in the Internet. With Droplet we intend to empower users with control over their data. Users should decide what and with whom they want to share.


With the myriad of IoT devices, more and more Internet-connected sensors will produce personal data. Enabling a secure storage and sharing of IoT data is imperative to its success.


How do we empower the user with ownership and fine-grained access control for IoT data without sacrificing performance or security?


We leverage the blockchain technology to bootstrap trust, for a distributed, secure, and resilient access control management. The permission-less blockchain provides auditability to our system.


Droplet enables reliable sharing among heterogeneous applications without intermediate trust entities, and features a cryptographically-protected fine-grained and scalable access control to data streams.

Time-series Data

Droplet handles time series data, ensuring confidentiality, integrity, and authenticity. After defined intervals data streams become immutable, such that even compromise of secret keys does not allow modification of previous stream data.


Droplet Code

GitHub repository


Hossein Shafagh

Hossein Shafagh is a research scientist at the Distributed Systems Group at ETH Zurich, Switzerland.

Anwar Hithnawi

Anwar Hithnawi is a research scientist at the NetSys Lab at UC Berkeley, USA.

Lukas Burkhalter

Lukas Burkhalter is a Ph.D. candidate and research assistant at the Distributed Systems Group at ETH Zurich, Switzerland.

Simon Duquennoy

Simon Duquennoy is a research scientist at RISE SICS (NES group), Sweden.

Sylvia Ratnasamy

Sylvia Ratnasamy is an Associate Professor at the NetSys Lab at UC Berkeley, USA.


ETH Zurich (Swiss Federal Institute of Technology Zurich)
Department of Computer Science
Distributed Systems Group
Universitaetstrasse 6
CH-8092 Zurich, Switzerland