David Naccache

cryptographer

Born in 1967 at Beersheba, David Naccache operates across the intersection of applied mathematics, law, and computer security. Holding citizenship in France, Israel, and Morocco, he has built a diverse career that spans roles as an engineer, cryptographer, and expert witness, while maintaining a broad academic footprint that includes institutions in Europe and Asia.

Academic and Research Trajectory

Naccache earned his doctorate in 1995 from Télécom Paris, following his training as an engineer. His academic career includes serving as a professor at Panthéon-Assas University and the École normale supérieure, where he remains a member of the Computer Laboratory. Beyond his primary appointments, he has held visiting positions and research roles at various international institutions, including Beijing Jiaotong University, University College London, and the Information Security Group at Royal Holloway, University of London.

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Contributions to Cryptology

His primary research focus lies in public-key cryptography and the cryptanalysis of digital signature schemes. Naccache is identified for his collaborative work with Jacques Stern, resulting in the development of the Naccache-Stern cryptosystem and the Naccache-Stern knapsack cryptosystem. In 2020, his professional body of work led to his selection as a Fellow of the International Association for Cryptologic Research for his contributions to the field and service to the association.

Industry Applications and Legal Expertise

Naccache has worked with numerous private sector entities, including IDEMIA, Visa Inc., Koninklijke Philips NV, Samsung Electronics, and the law firm Jones Day. In 2004, working with Claire Whelan at Gemplus International, he utilized image processing to identify redacted details in a declassified 2001 presidential briefing. His work frequently involves reverse engineering and security analysis, and he acts as an expert witness within legal contexts.

Professional Standing

In 2013, Naccache was appointed a Knight of the National Order of Merit. He maintains affiliations with the Institut Universitaire de France and has completed studies at the Institut des hautes études de défense nationale and the Institute of Advanced Studies for Science and Technology. Fluent in French, Italian, Spanish, English, Czech, Hebrew, and Arabic, he bridges multidisciplinary fields including security, law, and electronics.

Fast facts

Questions readers ask

What is David Naccache best known for in cryptography?

He is recognized for his research in public-key cryptography and the development of the Naccache-Stern cryptosystem.

What was the outcome of the 2021 legal challenge involving Naccache?

The lawsuit, which concerned a report Naccache produced for Genevrier Laboratories, was declined by the Cour supérieure du Québec on August 28, 2024, with the court citing concerns regarding defamatory tourism.

Achievements

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