Signal is an encrypted communications application for Android and iOS. There is a desktop plugin for Google Chrome as well (beginning from beta version published 7. April 2016)
Evaluation (10 December 2018)
Signal is the successor of an encrypted voice calling app called RedPhone and an encrypted texting program called TextSecure, after 2015 it has been called Signal.Signal is an encrypted communications application for Android and iOS. There is a DeskTop plugin for Google Chrome as well.
, iOS, mac, Windows and Linux platforms. It uses the Internet to send one-to-one and group messages, which can include images and video messages, and make one-to-one voice and video calls. Signal uses standard cellular mobile numbers as identifiers, and uses end-to-end encryption to secure all communications to other Signal users.
Signal is the successor of an encrypted voice calling app called RedPhone and an encrypted texting program called TextSecure, after 2015 it has been called Signal. Signal is developed by Open Whisper Systems. Source code of Signal is published under GPLv3 license.
- TOS: (version: Updated May 25, 2018) https://signal.org/legal/#terms-of-service
Evaluation (23 December 2020)
End to end encryption
Interoperability with other messaging software
Encryption for messages and phone calls
The complete source code of the Signal clients for Android, iOS and Google Chrome is available on GitHub under a free software license
Free licencing licensing enables interested parties to examine the code
Possibility for Group Conversations
Enclosing Multimedia is possible
Signal demands that the primary device is a Android or iOS phone, with an Internet connection
- Login happens with one´s mobile number. The service will be activated via SMS. The service is used via the mobile app.
- Signal demands that the primary device is a Android or iOS phone, with an Internet connection
- Signal.org https://signal.org/
- Signal is developed by a software group called Open Whisper Systems. The group is funded by a combination of donations and grants, and all of its products are published as free and open-source software.
- WhatsApp, Telegram, Chatsecure, Bleep
In this service Mobile Apps will send so called end to end (forward secrecy, end-to-end), encrypted messages, service quite is alike with WhatsApp, which is propably more known by public. Service is well protected for Man-In-the-Middle attacks and eavesdropping.
Revenue logic: The The group is funded by a combination of donations and grantsand crowd funding, and all of its products are published as free and open-source software. Different Foundations also support OpenWhisperSystemOpen Whisper System. Technical description of Signal can be found: http://support.whispersystems.org
Security and Privacy: All program code can be revievew at GitHub. Signal may be the only one this kind of software, which code can be reviewed entirely (including Proxy Servers. ?)
Service uses centralized Proxy Server which transmits messages and checks from users address book if communication contacts are using Signal. Location and compositoin of Proxies are not available, propably those are in U.S but messages stay encypted encrypted in transmission. Some data for example time stamps, public encryption key, PUSH-ID and IP address may be captured by authorities.
Possible communication companies are compaired compared using users address books from mobile phones and users address books from Signal´s customer database. Comparision Comparison algorithm is said to be one way procedure in a way users adress address book can not be exposed from server.