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Sybil Attack
A Sybil attack is a type of attack on a computer network service in which an attacker subverts the service's reputation system by creating a large number of pseudonymous identities and uses them to gain a disproportionately large influence. It is named after the subject of the book '' Sybil'', a case study of a woman diagnosed with dissociative identity disorder. The name was suggested in or before 2002 by Brian Zill at Microsoft Research. The term pseudospoofing had previously been coined by L. Detweiler on the Cypherpunks mailing list and used in the literature on peer-to-peer systems for the same class of attacks prior to 2002, but this term did not gain as much influence as "Sybil attack". Description The Sybil attack in computer security is an attack wherein a reputation system is subverted by creating multiple identities. A reputation system's vulnerability to a Sybil attack depends on how cheaply identities can be generated, the degree to which the reputation system accept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Service
In computer networking, a network service is an application running at the network layer and above, that provides data storage, manipulation, presentation, communication or other capability which is often implemented using a client–server or peer-to-peer architecture based on application layer network protocols. Each service is usually provided by a server component running on one or more computers (often a dedicated server computer offering multiple services) and accessed via a network by client components running on other devices. However, the client and server components can both be run on the same machine. Clients and servers will often have a user interface, and sometimes other hardware associated with it. Examples Examples are the Domain Name System (DNS) which translates domain names to Internet Protocol (IP) addresses and the Dynamic Host Configuration Protocol (DHCP) to assign networking configuration information to network hosts. Authentication servers identify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threat (computer Security)
In computer security, a threat is a potential negative action or event enabled by a vulnerability that results in an unwanted impact to a computer system or application. A threat can be either a negative "intentional" event (i.e. hacking: an individual cracker or a criminal organization) or an "accidental" negative event (e.g. the possibility of a computer malfunctioning, or the possibility of a natural disaster event such as an earthquake, a fire, or a tornado) or otherwise a circumstance, capability, action, or event ( incident is often used as a blanket term). A ''threat actor'' who is an individual or group that can perform the threat action, such as exploiting a vulnerability to actualise a negative impact. An '' exploit'' is a vulnerability that a threat actor used to cause an incident. Standard definitions A more comprehensive definition, tied to an Information assurance point of view, can be found in "''Federal Information Processing Standards (FIPS) 200, Minimum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threshold Cryptosystem
A threshold cryptosystem, the basis for the field of threshold cryptography, is a cryptosystem that protects information by encrypting it and distributing it among a cluster of fault-tolerant computers. The message is encrypted using a public key, and the corresponding private key is shared among the participating parties. With a threshold cryptosystem, in order to decrypt an encrypted message or to sign a message, several parties (more than some threshold number) must cooperate in the decryption or signature protocol. History Perhaps the first system with complete threshold properties for a trapdoor function (such as RSA) and a proof of security was published in 1994 by Alfredo De Santis, Yvo Desmedt, Yair Frankel, and Moti Yung. Historically, only organizations with very valuable secrets, such as certificate authorities, the military, and governments made use of this technology. One of the earliest implementations was done in the 1990s by Certco for the planned deployment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Validation Authority
In public key infrastructure, a validation authority (VA) is an entity that provides a service used to verify the validity or revocation status of a digital certificate per the mechanisms described in the X.509 standard and (page 69). Application The dominant method used for this purpose is to host a certificate revocation list (CRL) for download via the HTTP or LDAP protocols. To reduce the amount of network traffic required for certificate validation, the OCSP protocol may be used instead. Advantages While this is a potentially labor-intensive process, the use of a dedicated validation authority allows for dynamic validation of certificates issued by an offline root certificate authority. While the root CA itself will be unavailable to network traffic, certificates issued by it can always be verified via the validation authority and the protocols mentioned above. The ongoing administrative overhead of maintaining the CRLs hosted by the validation authority is typically minim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Censorship
Censorship is the suppression of speech, public communication, or other information. This may be done on the basis that such material is considered objectionable, harmful, sensitive, or "inconvenient". Censorship can be conducted by governments and private institutions. When an individual such as an author or other creator engages in censorship of their own works or speech, it is referred to as ''self-censorship''. General censorship occurs in a variety of different media, including speech, books, music, films, and other arts, Newspaper, the press, radio, television, and the Internet for a variety of claimed reasons including national security, to control obscenity, pornography, and hate speech, to protect children or other vulnerable groups, to promote or restrict political or religious views, and to prevent Defamation, slander and Defamation, libel. Specific rules and regulations regarding censorship vary between Legal Jurisdiction, legal jurisdictions and/or private organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anonymity
Anonymity describes situations where the acting person's identity is unknown. Anonymity may be created unintentionally through the loss of identifying information due to the passage of time or a destructive event, or intentionally if a person chooses to withhold their identity. There are various situations in which a person might choose to remain anonymous. Acts of charity have been performed anonymously when benefactors do not wish to be acknowledged. A person who feels threatened might attempt to mitigate that threat through anonymity. A witness to a crime might seek to avoid retribution, for example, by anonymously calling a crime tipline. In many other situations (like conversation between strangers, or buying some product or service in a shop), anonymity is traditionally accepted as natural. Some writers have argued that the term "namelessness", though technically correct, does not capture what is more centrally at stake in contexts of anonymity. The important idea here is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Address Translation
Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic Router (computing), routing device. The technique was initially used to bypass the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced but could not route the network's address space. It is a popular and essential tool in conserving global address space in the face of IPv4 address exhaustion. One Internet-routable IP address of a NAT gateway can be used for an entire private network. As network address translation modifies the IP address information in packets, NAT implementations may vary in their specific behavior in various addressing cases and their effect on network traffic. Vendors of equipment containing NAT implementations do not commonly document the specifics of NAT behavior. History Internet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrier-grade NAT
Carrier-grade NAT (CGN or CGNAT), also known as large-scale NAT (LSN), is a type of network address translation (NAT) used by ISPs in IPv4 network design. With CGNAT, end sites, in particular residential networks, are configured with private network addresses that are translated to public IPv4 addresses by middlebox network address translator devices embedded in the network operator's network, permitting the sharing of small pools of public addresses among many end users. This essentially repeats the traditional customer-premise NAT function at the ISP level. Carrier-grade NAT is often used for mitigating IPv4 address exhaustion. One use scenario of CGN has been labeled as NAT444, because some customer connections to Internet services on the public Internet would pass through three different IPv4 addressing domains: the customer's own private network, the carrier's private network and the public Internet. Another CGN scenario is Dual-Stack Lite, in which the carrier's network ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Social Exclusion
Social exclusion or social marginalisation is the social disadvantage and relegation to the fringe of society. It is a term that has been used widely in Europe and was first used in France in the late 20th century. In the EU context, the European Commission defines it as ''"a situation whereby a person is prevented (or excluded) from contributing to and benefiting from economic and social progress"''. It is used across disciplines including education, sociology, psychology, healthcare, politics and economics. Social exclusion is the process in which individuals are blocked from (or denied full access to) various rights, opportunities and resources that are normally available to members of a different group, and which are fundamental to social integration and observance of human rights within that particular group (e.g. due process). Alienation or disenfranchisement resulting from social exclusion can be connected to a person's social class, race, skin color, religious aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Address Spoofing
In computer networking, IP address spoofing or IP spoofing is the creation of Internet Protocol (IP) packets with a false source IP address, for the purpose of impersonating another computing system. Background The basic protocol for sending data over the Internet network and many other computer networks is the Internet Protocol (IP). The protocol specifies that each IP packet must have a header which contains (among other things) the IP address of the sender of the packet. The source IP address is normally the address that the packet was sent from, but the sender's address in the header can be altered, so that to the recipient it appears that the packet came from another source. The protocol requires the receiving computer to send back a response to the source IP address therefore spoofing is mainly used when the sender can anticipate the network response or does not care about the response. The source IP address provides only limited information about the sender. It may pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMS Spoofing
SMS spoofing is a technology which uses the short message service (SMS), available on most mobile phones and personal digital assistant A personal digital assistant (PDA) is a multi-purpose mobile device which functions as a personal information manager. Following a boom in the 1990s and 2000s, PDAs were mostly displaced by the widespread adoption of more highly capable smar ...s, to set who the message appears to come from by replacing the originating mobile number (Sender ID) with alphanumeric text. Spoofing has both legitimate uses (setting the company name from which the message is being sent, setting your own mobile number, or a product name) and illegitimate uses (such as impersonating another person, company, product). This can also send "mysterious" messages that look like they are from legitimate numbers or contacts. How SMS spoofing is carried out SMS Spoofing occurs when a sender manipulates address information. Often it is done in order to impersonate a user t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface identification, and location addressing. Internet Protocol version 4 (IPv4) was the first standalone specification for the IP address, and has been in use since 1983. IPv4 addresses are defined as a 32-bit number, which became too small to provide enough addresses as the internet grew, leading to IPv4 address exhaustion over the 2010s. Its designated successor, IPv6, uses 128 bits for the IP address, giving it a larger address space. Although IPv6 deployment has been ongoing since the mid-2000s, both IPv4 and IPv6 are still used side-by-side . IP addresses are usually displayed in a human-readable notation, but systems may use them in various different computer number formats. CIDR notation can also be used to designate how much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
