Mele Gasakis, Max Schmidt: Beyond Cryptographic Routing: The Echo Protocol in the new Era of Exponential Encryption (EEE) – A comprehensive essay about the Sprinkling Effect of Cryptographic Echo Discovery (SECRED) and further innovations in cryptography around the Echo Applications Smoke, SmokeStack, Spot-On, Lettera and GoldBug Crypto Chat Messenger addressing Encryption, Graph-Theory, Routing and the change from Mix-Networks like Tor or I2P to Peer-to-Peer-Flooding-Networks like the Echo respective to Friend-to-Friend Trust-Networks like they are built over the POPTASTIC protocol, ISBN 978-3-7481-5198-2, Norderstedt 2018. English / Auflage. Norderstedt 2018, S.304 (kit.edu).
David Adams, Ann-Kathrin Maier: BIG SEVEN Study, open source crypto-messengers to be compared – or: Comprehensive Confidentiality Review & Audit: Encrypting E-Mail-Client & Secure Instant Messenger, Descriptions, tests and analysis reviews of 20 functions of the applications based on the essential fields and methods of evaluation of the 8 major international audit manuals for IT security investigations including 38 figures and 87 tables. English / German Language, Version 1.1 Auflage. Tokio / München 2016, S.305 (sf.net [PDF]).
