Paper 2019/981

Traceback for End-to-End Encrypted Messaging

Nirvan Tyagi, Ian Miers, and Thomas Ristenpart

Abstract

Messaging systems are used to spread misinformation and other malicious content, often with dire consequences. End-to-end encryption improves privacy but hinders content-based moderation and, in particular, obfuscates the original source of malicious content. We introduce the idea of message traceback, a new cryptographic approach that enables platforms to simultaneously provide end-to-end encryption while also being able to track down the source of malicious content reported by users. We formalize functionality and security goals for message traceback, and detail two constructions that allow revealing a chain of forwarded messages (path traceback) or the entire forwarding tree (tree traceback). We implement and evaluate prototypes of our traceback schemes to highlight their practicality, and provide a discussion of deployment considerations.

Metadata
Available format(s)
PDF
Category
Applications
Publication info
Published elsewhere. Minor revision. CCS 2019
DOI
10.1145/3319535.3354243
Keywords
end-to-end encrypted messaginganonymitytracingabuse reportingmessage franking
Contact author(s)
nirvan tyagi @ gmail com
History
2019-08-29: received
Short URL
https://ia.cr/2019/981
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2019/981,
      author = {Nirvan Tyagi and Ian Miers and Thomas Ristenpart},
      title = {Traceback for End-to-End Encrypted Messaging},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/981},
      year = {2019},
      doi = {10.1145/3319535.3354243},
      url = {https://eprint.iacr.org/2019/981}
}
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