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Password
A password, sometimes called a passcode, is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of password-protected services that a typical individual accesses can make memorization of unique passwords for each service impractical. Using the terminology of the NIST Digital Identity Guidelines, the secret is held by a party called the ''claimant'' while the party verifying the identity of the claimant is called the ''verifier''. When the claimant successfully demonstrates knowledge of the password to the verifier through an established authentication protocol, the verifier is able to infer the claimant's identity. In general, a password is an arbitrary String (computer science), string of character (computing), characters including letters, digits, or other symbols. If the permissible characters are constrained to be numeric, the corresponding secret is sometimes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (cryptography)
In cryptography, a salt is random data fed as an additional input to a one-way function that hashes data Data ( , ) are a collection of discrete or continuous values that convey information, describing the quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted for ..., a password or passphrase. Salting helps defend against attacks that use precomputed tables (e.g. rainbow tables), by vastly growing the size of table needed for a successful attack. It also helps protect passwords that occur multiple times in a database, as a new salt is used for each password instance. Additionally, salting does not place any burden on users. Typically, a unique salt is randomly generated for each password. The salt and the password (or its version after key stretching) are concatenated and fed to a cryptographic hash function, and the output hash value is then stored with the salt in a database. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passphrase
A passphrase is a sequence of words or other text used to control access to a computer system, program or data. It is similar to a password in usage, but a passphrase is generally longer for added security. Passphrases are often used to control both access to, and the operation of, Cryptography, cryptographic programs and systems, especially those that derive an encryption key from a passphrase. The origin of the term is by analogy with ''password''. The modern concept of passphrases is believed to have been invented by Sigmund N. Porter in 1982. Security Source: Considering that the information entropy, entropy of written English is less than 1.1 bits per character, passphrases can be relatively weak. NIST has estimated that the 23-character passphrase "IamtheCapitanofthePina4" contains a 45-bit strength. The equation employed here is: : 4 bits (1st character) + 14 bits (characters 2–8) + 18 bits (characters 9–20) + 3 bits (characters 21–23) + 6 bits (bonus f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictionary Attack
In cryptanalysis and computer security, a dictionary attack is an attack using a restricted subset of a keyspace to defeat a cipher or authentication mechanism by trying to determine its decryption key or passphrase, sometimes trying thousands or millions of likely possibilities often obtained from lists of past security breaches. Technique A dictionary attack is based on trying all the strings in a pre-arranged listing. Such attacks originally used words found in a dictionary (hence the phrase ''dictionary attack''); however, now there are much larger lists available on the open Internet containing hundreds of millions of passwords recovered from past data breaches. There is also cracking software that can use such lists and produce common variations, such as substituting numbers for similar-looking letters. A dictionary attack tries only those possibilities which are deemed most likely to succeed. Dictionary attacks often succeed because many people have a tendency to choose s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hacker (computer Security)
A security hacker or security researcher is someone who explores methods for breaching or bypassing defenses and exploiting weaknesses in a computer system or network. Hackers may be motivated by a multitude of reasons, such as profit, protest, sabotage, information gathering, challenge, recreation, or evaluation of a system weaknesses to assist in formulating defenses against potential hackers. Longstanding controversy surrounds the meaning of the term "hacker". In this controversy, computer programmers reclaim the term ''hacker'', arguing that it refers simply to someone with an advanced understanding of computers and computer networks, and that ''cracker'' is the more appropriate term for those who break into computers, whether computer criminals ( black hats) or computer security experts ( white hats). A 2014 article noted that "the black-hat meaning still prevails among the general public". The subculture that has evolved around hackers is often referred to as the "co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Authentication Protocol
An authentication protocol is a type of computer communications protocol or cryptographic protocol specifically designed for transfer of authentication data between two entities. It allows the receiving entity to authenticate the connecting entity (e.g. Client connecting to a Server) as well as authenticate itself to the connecting entity (Server to a client) by declaring the type of information needed for authentication as well as syntax. It is the most important layer of protection needed for secure communication within computer networks. Purpose With the increasing amount of trustworthy information being accessible over the network, the need for keeping unauthorized persons from access to this data emerged. Stealing someone's identity is easy in the computing world - special verification methods had to be invented to find out whether the person/computer requesting data is really who he says he is. The task of the authentication protocol is to specify the exact series of steps n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer User
A user is a person who uses a computer or Computer network, network Service (systems architecture), service. A user often has a user account and is identified to the system by a username (or user name). Some software products provide services to other systems and have no direct end users. End user End users are the ultimate human users (also referred to as Operator (profession), operators) of a software product. The end user stands in contrast to users who support or maintain the product such as sysops, database administrators and computer technicians. The term is used to abstract and distinguish those who only use the software from the developers of the system, who enhance the software for end users. In user-centered design, it also distinguishes the software operator from the client who pays for its development and other Stakeholder (corporate), stakeholders who may not directly use the software, but help establish its Software requirements, requirements. This abstracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User (computing)
A user is a person who uses a computer or network service. A user often has a user account and is identified to the system by a username (or user name). Some software products provide services to other systems and have no direct end users. End user End users are the ultimate human users (also referred to as operators) of a software product. The end user stands in contrast to users who support or maintain the product such as sysops, database administrators and computer technicians. The term is used to abstract and distinguish those who only use the software from the developers of the system, who enhance the software for end users. In user-centered design, it also distinguishes the software operator from the client who pays for its development and other stakeholders who may not directly use the software, but help establish its requirements. This abstraction is primarily useful in designing the user interface, and refers to a relevant subset of characteristics t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compatible Time-Sharing System
The Compatible Time-Sharing System (CTSS) was the first general purpose time-sharing operating system. Compatible Time Sharing referred to time sharing which was compatible with batch processing; it could offer both time sharing and batch processing concurrently. CTSS was developed at the MIT Computation Center ("Comp Center"). CTSS was first demonstrated on MIT's modified IBM 709 in November 1961. The hardware was replaced with a modified IBM 7090 in 1962 and later a modified IBM 7094 called the "blue machine" to distinguish it from the Project MAC CTSS IBM 7094. Routine service to MIT Comp Center users began in the summer of 1963 and was operated there until 1968. A second deployment of CTSS on a separate IBM 7094 that was received in October 1963 (the "red machine") was used early on in Project MAC until 1969 when the red machine was moved to the Information Processing Center and operated until July 20, 1973. CTSS ran on only those two machines; however, there were remot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Control
In physical security and information security, access control (AC) is the action of deciding whether a subject should be granted or denied access to an object (for example, a place or a resource). The act of ''accessing'' may mean consuming, entering, or using. It is often used interchangeably with authorization, although the authorization may be granted well in advance of the access control decision. Access control on digital platforms is also termed admission control. The protection of external databases is essential to preserve digital security. Access control is considered to be a significant aspect of privacy that should be further studied. Access control policy (also access policy) is part of an organization’s security policy. In order to verify the access control policy, organizations use an access control model. General security policies require designing or selecting appropriate security controls to satisfy an organization's risk appetite - access policies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crypt (Unix)
In Unix computing, crypt or enigma is a utility program used for encryption. Due to the ease of breaking it, it is considered to be obsolete. The program is usually used as a filter, and it has traditionally been implemented using a "rotor machine" algorithm based on the Enigma machine. It is considered to be cryptographically far too weak to provide any security against brute-force attacks by modern, commodity personal computers. Some versions of Unix shipped with an even weaker version of the ''crypt(1)'' command in order to comply with contemporaneous laws and regulations that limited the exportation of cryptographic software. Some of these were simply implementations of the Caesar cipher (effectively no more secure than ROT13, which is implemented as a Caesar cipher with a well-known key). History Cryptographer Robert Morris wrote a M-209-based , which first appeared in Version 3 Unix, to encourage codebreaking experiments; Morris managed to break by hand. Dennis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logging (computer Security)
In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system or program by identifying and authenticating themselves. Typically, user credentials consist of a username and a password. These credentials themselves are sometimes referred to as ''a'' login. Modern secure systems often require a second factor, such as email or SMS confirmation for extra security. Social login allows a user to use an existing cell phone number, or user credentials from another email or social networking service to sign in or create an account on a new website. When access is no longer needed, the user can log out, log off, sign out or sign off. Procedure Logging in is usually used to enter a specific page, website, platform or application, which trespassers cannot see. Once the user is logged in, the login token may be used to track what actions the user has taken while connected to the site. Loggin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Morris (cryptographer)
Robert Morris (July 25, 1932 – June 26, 2011) was an American cryptographer and computer scientist. His name sometimes appears with a middle initial H that he adopted informally. __TOC__ Family and education Morris was born in Boston, Massachusetts. His parents were Walter W. Morris, a salesman, and Helen Kelly Morris, a homemaker. He received a bachelor's degree in mathematics from Harvard University in 1957 and a master's degree in applied mathematics from Harvard in 1958. He married Anne Farlow, and they had three children together: Robert Tappan Morris (author of the 1988 Morris worm), Meredith Morris, and Benjamin Morris. Bell Labs From 1960 until 1986, Morris was a researcher at Bell Labs and worked on Multics and later Unix. Using the TMG (language), TMG compiler-compiler, Morris, together with McIlroy, developed the early implementation of the PL/I compiler called EPL for the Multics project. The pair also contributed a version of TYPSET and RUNOFF, runoff text-format ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
