AIM was an instant messaging and presence computer program created by AOL, which used the proprietary OSCAR instant messaging protocol and the TOC protocol to allow registered users to communicate in real time.
Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. PGP is used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitions and to increase the security of e-mail communications. Phil Zimmermann developed PGP in 1991.
Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and triggers a transmission to the recipient(s), who are all connected on a common network. It differs from email in that conversations over instant messaging happen in real-time. Most modern IM applications use push technology and also add other features such as emojis, file transfer, chatbots, voice over IP, or video chat capabilities.
End-to-end encryption (E2EE) is a private communication system in which only communicating users can participate. As such, no one, including the communication system provider, telecom providers, Internet providers or malicious actors, can access the cryptographic keys needed to converse.
NSA Suite B Cryptography was a set of cryptographic algorithms promulgated by the National Security Agency as part of its Cryptographic Modernization Program. It was to serve as an interoperable cryptographic base for both unclassified information and most classified information.
Off-the-Record Messaging (OTR) is a cryptographic protocol that provides encryption for instant messaging conversations. OTR uses a combination of AES symmetric-key algorithm with 128 bits key length, the Diffie–Hellman key exchange with 1536 bits group size, and the SHA-1 hash function. In addition to authentication and encryption, OTR provides forward secrecy and malleable encryption.
Network Security Services (NSS) is a collection of cryptographic computer libraries designed to support cross-platform development of security-enabled client and server applications with optional support for hardware TLS/SSL acceleration on the server side and hardware smart cards on the client side. NSS provides a complete open-source implementation of cryptographic libraries supporting Transport Layer Security (TLS) / Secure Sockets Layer (SSL) and S/MIME. NSS releases prior to version 3.14 are tri-licensed under the Mozilla Public License 1.1, the GNU General Public License, and the GNU Lesser General Public License. Since release 3.14, NSS releases are licensed under GPL-compatible Mozilla Public License 2.0.
eBuddy is a privately held Dutch software company that offers instant messaging services. As of 2011, eBuddy reported 100 million downloads. The company's flagship service is XMS, a proprietary cross-platform instant messaging service. After some changes of ownership, the company is now again owned by its original founders, Onno Bakker and Jan-Joost Rueb.
BBM, also known by its full name BlackBerry Messenger, was a consumer-oriented proprietary mobile instant messenger and videotelephony application service originally developed by BlackBerry Limited and later briefly by Indonesian company Emtek under licence. Initially it was included and offered on BlackBerry devices before it was expanded cross-platform. BBM was shut down on 31 May 2019; the company since continues to offer the paid enterprise edition, BBM Enterprise.
The following outline is provided as an overview of and topical guide to cryptography:
There are various implementations of the Advanced Encryption Standard, also known as Rijndael.
Cryptocat is a discontinued open-source desktop application intended to allow encrypted online chatting available for Windows, OS X, and Linux. It uses end-to-end encryption to secure all communications to other Cryptocat users. Users are given the option of independently verifying their buddies' device lists and are notified when a buddy's device list is modified and all updates are verified through the built-in update downloader.
Wickr is an American software company based in New York City, known for its instant messenger application of the same name. The Wickr instant messaging apps allow users to exchange end-to-end encrypted and content-expiring messages, and are designed for iOS, Android, Mac, Windows, and Linux operating systems. On June 25, 2021, Wickr was acquired by Amazon Web Services.
TextSecure was an encrypted messaging application for Android that was developed from 2010 to 2015. It was a predecessor to Signal and the first application to use the Signal Protocol, which has since been implemented into WhatsApp and other applications. TextSecure used end-to-end encryption to secure the transmission of text messages, group messages, attachments and media messages to other TextSecure users.
Threema is a paid cross-platform encrypted instant messaging app developed by Threema GmbH in Switzerland and launched in 2012. The service operates on a decentralized architecture and offers end-to-end encryption. Users can make voice and video calls, send photos, files, and voice notes, share locations, and make groups. Unlike many other popular secure messaging apps, Threema does not require phone numbers or email address for registration, only a one-time purchase. Threema is available on iOS and Android and has clients for Windows, macOS, Linux, and can be accessed via web browser but requires a mobile app to function.
OMEMO is an extension to the Extensible Messaging and Presence Protocol (XMPP) for multi-client end-to-end encryption developed by Andreas Straub. According to Straub, OMEMO uses the Double Ratchet Algorithm "to provide multi-end to multi-end encryption, allowing messages to be synchronized securely across multiple clients, even if some of them are offline". The name "OMEMO" is a recursive acronym for "OMEMO Multi-End Message and Object Encryption". It is an open standard based on the Double Ratchet Algorithm and the Personal Eventing Protocol . OMEMO offers future and forward secrecy and deniability with message synchronization and offline delivery.
In cryptography, the Double Ratchet Algorithm is a key management algorithm that was developed by Trevor Perrin and Moxie Marlinspike in 2013. It can be used as part of a cryptographic protocol to provide end-to-end encryption for instant messaging. After an initial key exchange it manages the ongoing renewal and maintenance of short-lived session keys. It combines a cryptographic so-called "ratchet" based on the Diffie–Hellman key exchange (DH) and a ratchet based on a key derivation function (KDF), such as a hash function, and is therefore called a double ratchet.
The Signal Protocol is a non-federated cryptographic protocol that provides end-to-end encryption for voice and instant messaging conversations. The protocol was developed by Open Whisper Systems in 2013 and was first 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" or Google who provides end-to-end encryption by default to all RCS-based conversations between users of their Messages app for one-to-one conversations. Facebook Messenger also say they offer the protocol for optional Secret Conversations, as does Skype for its Private Conversations.
The IBM 4769 PCIe Cryptographic Coprocessor is a hardware security module (HSM) that includes a secure cryptoprocessor implemented on a high-security, tamper resistant, programmable PCIe board. Specialized cryptographic electronics, microprocessor, memory, and random number generator housed within a tamper-responding environment provide a highly secure subsystem in which data processing and cryptography can be performed. Sensitive key material is never exposed outside the physical secure boundary in a clear format.
Hugo Krawczyk is an Argentine-Israeli cryptographer best known for co-inventing the HMAC message authentication algorithm and contributing in fundamental ways to the cryptographic architecture of central Internet standards, including IPsec, IKE, and SSL/TLS. In particular, both IKEv2 and TLS 1.3 use Krawczyk’s SIGMA protocol as the cryptographic core of their key exchange procedures. He has also contributed foundational work in the areas of threshold and proactive cryptosystems and searchable symmetric encryption, among others.
