Key derivation functionIn cryptography, a key derivation function (KDF) is a cryptographic algorithm that derives one or more secret keys from a secret value such as a master key, a password, or a passphrase using a pseudorandom function (which typically uses a cryptographic hash function or block cipher). KDFs can be used to stretch keys into longer keys or to obtain keys of a required format, such as converting a group element that is the result of a Diffie–Hellman key exchange into a symmetric key for use with AES.
Simple Mail Transfer ProtocolThe Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typically use SMTP only for sending messages to a mail server for relaying, and typically submit outgoing email to the mail server on port 587 or 465 per . For retrieving messages, IMAP (which replaced the older POP3) is standard, but proprietary servers also often implement proprietary protocols, e.
Secure Remote Password protocolThe Secure Remote Password protocol (SRP) is an augmented password-authenticated key exchange (PAKE) protocol, specifically designed to work around existing patents. Like all PAKE protocols, an eavesdropper or man in the middle cannot obtain enough information to be able to brute-force guess a password or apply a dictionary attack without further interactions with the parties for each guess. Furthermore, being an augmented PAKE protocol, the server does not store password-equivalent data.
Targeted surveillanceTargeted surveillance (or targeted interception) is a form of surveillance, such as wiretapping, that is directed towards specific persons of interest, and is distinguishable from mass surveillance (or bulk interception). Both untargeted and targeted surveillance is routinely accused of treating innocent people as suspects in ways that are unfair, of violating human rights, international treaties and conventions as well as national laws, and of failing to pursue security effectively.
Security dilemmaIn international relations, the security dilemma (also referred to as the spiral model) is when the increase in one state's security (such as increasing its military strength) leads other states to fear for their own security (because they do not know if the security-increasing state intends to use its growing military for offensive purposes). Consequently, security-increasing measures can lead to tensions, escalation or conflict with one or more other parties, producing an outcome which no party truly desires; a political instance of the prisoner's dilemma.
Matrix (protocol)Matrix (sometimes stylized as [matrix]) is an open standard and communication protocol for real-time communication. It aims to make real-time communication work seamlessly between different service providers, in the way that standard Simple Mail Transfer Protocol email currently does for store-and-forward email service, by allowing users with accounts at one communications service provider to communicate with users of a different service provider via online chat, voice over IP, and videotelephony.
Secure cryptoprocessorA secure cryptoprocessor is a dedicated computer-on-a-chip or microprocessor for carrying out cryptographic operations, embedded in a packaging with multiple physical security measures, which give it a degree of tamper resistance. Unlike cryptographic processors that output decrypted data onto a bus in a secure environment, a secure cryptoprocessor does not output decrypted data or decrypted program instructions in an environment where security cannot always be maintained.
Comparison of user features of messaging platformsComparison of user features of messaging platforms refers to a comparison of all the various user features of various electronic instant messaging platforms. This includes a wide variety of resources; it includes standalone apps, platforms within websites, computer software, and various internal functions available on specific devices, such as iMessage for iPhones. This entry includes only the features and functions that shape the user experience for such apps.
Homeland securityHomeland security is an American national security term for "the national effort to ensure a homeland that is safe, secure, and resilient against terrorism and other hazards where American interests, aspirations, and ways of life can thrive" to the "national effort to prevent terrorist attacks within the United States, reduce the vulnerability of the U.S. to terrorism, and minimize the damage from attacks that do occur." According to an official work published by the Congressional Research Service in 2013, the "Homeland security" term's definition has varied over time.
