EphPub: toward robust Ephemeral Publishing

Claude Castelluccia*, Emiliano De Cristofaro, Aurélien Francillon, Mohamed-Ali Kaafar

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

22 Citations (Scopus)


The increasing amount of personal and sensitive information disseminated over the Internet prompts commen-surately growing privacy concerns. Digital data often lingers indefinitely and users lose its control. This motivates the desire to restrict content availability to an expiration time set by the data owner. This paper presents and formalizes the notion of Ephemeral Publishing (EphPub), to prevent the access to expired content. We propose an efficient and robust protocol that builds on the Domain Name System (DNS) and its caching mechanism. With EphPub, sensitive content is published encrypted and the key material is distributed, in a steganographic manner, to randomly selected and independent resolvers. The availability of content is then limited by the evanescence of DNS cache entries. The EphPub protocol is transparent to existing applications, and does not rely on trusted hardware, centralized servers, or user proactive actions. We analyze its robustness and show that it incurs a negligible overhead on the DNS infrastructure. We also perform a large-scale study of the caching behavior of 900K open DNS resolvers. Finally, we propose Firefox and Thunderbird extensions that provide ephemeral publishing capabilities, as well as a command-line tool to create ephemeral files.

Original languageEnglish
Title of host publication2011 19th IEEE International Conference on Network Protocols, ICNP 2011
Number of pages11
Publication statusPublished - 2011
Externally publishedYes
Event2011 19th IEEE International Conference on Network Protocols, ICNP 2011 - Vancouver, BC, Canada
Duration: 17 Oct 201120 Oct 2011


Conference2011 19th IEEE International Conference on Network Protocols, ICNP 2011
CityVancouver, BC


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