Two cents for strong anonymity: The anonymous post-office protocol

Nethanel Gelernter, Amir Herzberg, Hemi Leibowitz

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

7 Scopus citations


We introduce the Anonymous Post-Office Protocol (AnonPoP), a practical strongly-anonymous messaging system. Its design effectively combines known techniques such as (synchronous) mix-cascade and constant sending rate, with several new techniques including request-pool, bad-server isolation and per-epoch mailboxes. AnonPoP offers strong anonymity against strong, globally-eavesdropping adversaries, that may also control multiple servers, including all-but-one servers in a mix-cascade. Significantly, AnonPoP’s anonymity holds even when clients may occasionally disconnect, which is essential for supporting mobile clients. AnonPoP is affordable, with monthly costs of 2 cents per client. It is also efficient with respect to latency, communication, and energy, making it suitable for mobile clients. We developed an API that allows other applications to use AnonPoP for adding strong anonymity. We evaluated AnonPoP in several experiments, including a ‘double-blinded’ usability study, a cloud-based deployment, and simulations.

Original languageEnglish
Title of host publicationCryptology and Network Security - 16th International Conference, CANS 2017, Revised Selected Papers
EditorsSrdjan Capkun, Sherman S.M. Chow
PublisherSpringer Verlag
Number of pages23
ISBN (Print)9783030026400
StatePublished - 2018
Event16th International Conference on Cryptology and Network Security, CANS 2017 - Hong Kong, China
Duration: 30 Nov 20172 Dec 2017

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume11261 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference16th International Conference on Cryptology and Network Security, CANS 2017
CityHong Kong

Bibliographical note

Publisher Copyright:
© Springer Nature Switzerland AG 2018.


Acknowledgments. We are grateful to George Danezis, Yossi Gilad, Hezi Moriel, Roee Shlomo, Bogdan Carbunar and the anonymous reviewers for their helpful and constructive feedback. This work was supported by the Israeli Ministry of Science and Technology.

FundersFunder number
Ministry of science and technology, Israel


    Dive into the research topics of 'Two cents for strong anonymity: The anonymous post-office protocol'. Together they form a unique fingerprint.

    Cite this