- CA-MI S.r.l.
- CERN [Genève]
- Cardiff University
- Carleton University
- Center for Advanced Security Research Darmstadt [Darmstadt]
- CentraleSupélec
- Centre National de la Recherche Scientifique
- Centre for Applied Research in Information Systems
- Centre for Cybercrime and Computer Security [Newcastle]
- Centre for Interactive Systems Research
- Centre for Quantum Computation and Intelligent Systems [Sydney]
- Chebyshev Laboratory
- Chercheur indépendant
- Chiba Institute of Technology
- Chinese Academy of Sciences [Changchun Branch]
- Chosun University
- Christian Doppler Laboratory for Security and Quality Improvement and Quality Improvement in the Production System Lifecycle
- City University of London
- College of Engineering and Science [Louisiana]
- College of Mathematics, Physics and Information Engineering [Jinhua]
- Colombian Center of Excellence and Appropriation on Big Data and Data Analytics
- Commonwealth Scientific and Industrial Research Organisation [Canberra]
- Computer Engineering Department
- Computer Graphics and HCI Group [Kaiserslautern]
- Computer Science [Louisiana]
- Computer Science and Communications Research Unit [Luxembourg]
- Concordia Institute for Information Systems Engineering
- Concordia University [Montreal]
- Consiglio Nazionale delle Ricerche [Milano]
- Council for Scientific and Industrial Research [Pretoria]
- Council for Scientific and Industrial Research [South Africa]
- Coventry University
- Cryptography and Computeralgebra, Department of Computer Science