This article is about encryption protocol. For messenger implementing this protocol, see Signal (messaging app). For the charitable foundation, see Signal Foundation.
Non-federated cryptographic protocol
Signal Protocol
Communication protocol
Purpose
End-to-end encrypted communications
Developer(s)
Signal Foundation
Based on
OTR, SCIMP[1]
Influenced
OMEMO, Matrix[2]
OSI layer
Application layer
Website
signal.org/docs
The Signal Protocol (formerly known as the TextSecure Protocol) is a non-federated cryptographic protocol that provides end-to-end encryption for voice and instant messaging conversations.[2] The protocol was developed by Open Whisper Systems in 2013[2] and was introduced in the open-source TextSecure app, which later became Signal. Several closed-source applications have implemented the protocol, such as WhatsApp, which is said to encrypt the conversations of "more than a billion people worldwide"[3] or Google who provides end-to-end encryption by default to all RCS-based conversations between users of their Google Messages app for one-to-one conversations.[4] Facebook Messenger also say they offer the protocol for optional Secret Conversations, as does Skype for its Private Conversations.
The protocol combines the Double Ratchet Algorithm, prekeys, and a triple Elliptic-curve Diffie–Hellman (3-DH) handshake,[5] and uses Curve25519, AES-256, and HMAC-SHA256 as primitives.[6]
^Cite error: The named reference advanced-ratcheting was invoked but never defined (see the help page).
^ abcErmoshina, Ksenia; Musiani, Francesca; Halpin, Harry (September 2016). "Internet Science". In Bagnoli, Franco; et al. (eds.). Internet Science. INSCI 2016. Lecture Notes in Computer Science. Vol. 9934. Florence, Italy: Springer. pp. 244–254. doi:10.1007/978-3-319-45982-0_22. ISBN 978-3-319-45982-0.
^"WhatsApp's Signal Protocol integration is now complete". Signal. Signal Blog. 2016. Archived from the original on 29 January 2021. Retrieved 5 April 2016.
^Cite error: The named reference :0 was invoked but never defined (see the help page).
The SignalProtocol (formerly known as the TextSecure Protocol) is a non-federated cryptographic protocol that provides end-to-end encryption for voice...
A signalingprotocol is a type of communications protocol for encapsulating the signaling between communication endpoints and switching systems to establish...
technology." Its subsidiary, Signal Messenger LLC, is responsible for the development of the Signal messaging app and the SignalProtocol. On February 21, 2018...
Signal Messenger LLC. He is also a co-author of the Signal Protocol encryption used by Signal, WhatsApp, Google Messages, Facebook Messenger, and Skype...
The Session Initiation Protocol (SIP) is a signalingprotocol used for initiating, maintaining, and terminating communication sessions that include voice...
to Point Protocol Secure Shell (SSH) SignalProtocol Transport Layer Security ZRTP List of cryptosystems Secure channel Security Protocols Open Repository...
digital signal via a medium that is wired, wireless, or fiber-optic. Transmission system technologies typically refer to physical layer protocol duties...
Serial Interface (SSI) protocol. (Note: Variations section describes operation of non-standard variants.) SPI has four logic signals (which may have alternative...
Marlinspike (Open Whisper Systems) in 2013 and introduced as part of the SignalProtocol in February 2014. The Double Ratchet Algorithm's design is based on...
RTP Control Protocol (RTCP) is a binary-encoded out-of-band signalingprotocol that functions alongside the Real-time Transport Protocol (RTP). Its basic...
(SIP), connection management protocol developed by the IETF H.323, one of the first VoIP call signaling and control protocols that found widespread implementation...
responsible for starting the development of the SignalProtocol and the Signal messaging app. In 2018, Signal Messenger was incorporated as an LLC by Moxie...
to choose from. For transmission, there is a physical connector and signalprotocol (see List of video connectors). A given physical link can carry certain...
lightweight IP-based protocol for session signaling with Cisco Unified Communications Manager, formerly named CallManager. The protocol architecture is similar...
users who wished to use the legacy 4–20 mA signals, but wanted to implement a "smart" protocol. The protocol was developed by Rosemount Inc., built off...
The protocol stack or network stack is an implementation of a computer networking protocol suite or protocol family. Some of these terms are used interchangeably...
developed from 2010 to 2015. It was a predecessor to Signal and the first application to use the SignalProtocol, which has since been implemented into WhatsApp...
Protocol on Road Signs and Signals. There is a European Agreement supplementing the 1949 Convention on Road Traffic, in addition to the 1949 Protocol...
Transport Protocol (RTP) specifies a general-purpose data format and network protocol for transmitting digital media streams on Internet Protocol (IP) networks...
Global Information