Post-doctoral fellow in advanced cryptography for 5G-based networks at Télécom Paris - 24 months

Job description

Who are we ?

Télécom Paris, a school of the IMT (Institut Mines-Télécom) and a founding member of the Institut Polytechnique de Paris, is one of the top 5 French general engineering schools.
The mainspring of Télécom Paris is to train, imagine and undertake to design digital models, technologies and solutions for a society and economy that respect people and their environment. The school is committed to providing an environment conducive to the development of all students and research professors, and is voluntarily and sustainably committed to an ambitious plan for social and ecological transition. It is working to increase the number of female research professors and to reduce the disparities between men and women.


As part of the Beyond 5G project, the INFRES department is working in the field of decentralised cryptography, a central topic for the C2 team.
For several reasons such as load balancing, coverage of extended geographic location and security, the 5G network has been designed in a multi-server architecture, based on the “edge computing paradigm”. It has also been adapted to be used in the IoT context, considering that some 5G devices are not very powerful. But those choices come with new threats for which we need adapted security tools.
Regarding data security, we have such advanced encryption techniques. Named homomorphic encryption, multi-party computation or functional encryption, they permit to both protect and use sensitive data, and we know now how to handle them in a multi-party setting. But those primitives have never been studied in the context of such a 5G-based network, with the constraints of 5G, and the one an edge computing system. Hence the first mission of the post doc: adapt advanced encryption techniques to 5G-based networks.
Delay-based cryptography introduces a notion of time into cryptographic protocols, by ensuring that a message cannot be read until a certain amount of time has elapsed. However, typically delay-based cryptography is constructed under the assumption that all parties (for example clients as well as a server) have enough computational power to efficiently compute a delay. To be able to use delay-based cryptography with low powered clients, i.e., within in the IoT space, this assumption is not realistic, and hence a different framework needs to be studied. This is the purpose of the second mission: study the concept of delay-based cryptography in the context of 5G-based networks.
Delay-based cryptography has been applied to some context, and solutions exist, in relation with several cryptographic tools, but the related work is very poor w.r.t. the above advanced encryption techniques, especially when applied to the multi-party setting. This gives the last technical mission of the post doc: design advanced encryption techniques with the delay-based property.


  • Conducts research assignments under departmental contracts in the field of cryptography
  • Participates in and ensures the completion of project deliverables
  • Supervises student projects and engineering internships
  • Publishes the results of its research work
  • Gives presentations and conferences
  • Is involved in learned or professional societies
  • Maintains close relations with academic institutions, research centers and companies

Job requirements

Required skills, experience, and knowledge:

  • In-depth theoretical and practical knowledge in the field of cryptography
  • Important skills on advanced encryption techniques
  • Knowledge on 5G
  • Fluency in English

Preferred skills, experience, and knowledge:

  • Public key cryptography and protocols
  • Security proofs in cryptography
  • Delay-based cryptography

Other abilities and skills:

  • Ability to work in a team, dialogue and writing skills
  • Interpersonal and pedagogical skills
  • Ability to synthesize

Candidates with the following qualifications may apply:
  • PhD or equivalent

Other information :
Application deadline: 31/12/2023
Type of job : 24 months fixed contract 
Full job description here

Scientific contact person: Sébastien Canard

Administrative contact person: Céline Laouenan

All our positions are open to people with disabilities.