Paper 2025/1951

What is Cryptography Hiding from Itself?

Diego F. Aranha, Aarhus University
Nikolas Melissaris, IRIF, CNRS & Université Paris Cité
Abstract

The European Commission's 2022 proposal for a regulation on child sexual abuse material, popularly labelled ChatControl, obliges online services to detect, report, and remove prohibited content, through client-side scanning. This paper examines the proposal as a case of undone science in computer security ethics: a domain where technical feasibility and rights-compatibility questions remain systematically underexplored. Combining legal analysis with philosophy of technology, the paper argues that client-side scanning transforms end-to-end encryption from a right to secrecy into a conditional privilege of use. By integrating Isaiah Berlin's concept of negative liberty, Langdon Winner’s account of the politics of artifacts, and David Hess’s notion of undone science, the analysis traces how design choices become moral constraints. The discussion situates the European debate within broader concerns about proportionality, epistemic selectivity, and the governance of digital infrastructures. Ultimately, the study shows that the controversy over ChatControl is not only about privacy or child protection but about the epistemic norms that define what counts as legitimate technological knowledge.

Metadata
Available format(s)
PDF
Category
Foundations
Publication info
Preprint.
Keywords
policyend-to-end encryptionE2EEsurveillanceethicsclient-side scanning
Contact author(s)
dfaranha @ cs au dk
nikolas @ irif fr
History
2025-10-20: approved
2025-10-19: received
See all versions
Short URL
https://ia.cr/2025/1951
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/1951,
      author = {Diego F. Aranha and Nikolas Melissaris},
      title = {What is Cryptography Hiding from Itself?},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1951},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1951}
}
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