In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall establishes a barrier between a trusted internal network and untrusted external network, such as the Internet. Firewalls are categorized as either network firewalls or host-based firewalls. Network run on network hardware. Host-based firewalls run on host computers and control network traffic out of those machines; the term firewall referred to a wall intended to confine a fire within a building. Uses refer to similar structures, such as the metal sheet separating the engine compartment of a vehicle or aircraft from the passenger compartment; the term was applied in the late 1980s to network technology that emerged when the Internet was new in terms of its global use and connectivity. The predecessors to firewalls for network security were the routers used in the late 1980s, because they separated networks from one another, thus halting the spread of problems from one network to another.
The first reported type of network firewall is called a packet filter. Packet filters act by inspecting packets transferred between computers; when a packet does not match the packet filter's set of filtering rules, the packet filter either drops the packet, or rejects the packet else it is allowed to pass. Packets may be filtered by source and destination network addresses, protocol and destination port numbers; the bulk of Internet communication in 20th and early 21st century used either Transmission Control Protocol or User Datagram Protocol in conjunction with well-known ports, enabling firewalls of that era to distinguish between, thus control, specific types of traffic, unless the machines on each side of the packet filter used the same non-standard ports. The first paper published on firewall technology was in 1988, when engineers from Digital Equipment Corporation developed filter systems known as packet filter firewalls. At AT&T Bell Labs, Bill Cheswick and Steve Bellovin continued their research in packet filtering and developed a working model for their own company based on their original first generation architecture.
From 1989–1990, three colleagues from AT&T Bell Laboratories, Dave Presotto, Janardan Sharma, Kshitij Nigam, developed the second generation of firewalls, calling them circuit-level gateways. Second-generation firewalls perform the work of their first-generation predecessors but maintain knowledge of specific conversations between endpoints by remembering which port number the two IP addresses are using at layer 4 of the OSI model for their conversation, allowing examination of the overall exchange between the nodes; this type of firewall is vulnerable to denial-of-service attacks that bombard the firewall with fake connections in an attempt to overwhelm the firewall by filling its connection state memory. Marcus Ranum, Wei Xu, Peter Churchyard released an application firewall known as Firewall Toolkit in October 1993; this became the basis for Gauntlet firewall at Trusted Information Systems. The key benefit of application layer filtering is that it can understand certain applications and protocols.
This is useful as it is able to detect if an unwanted application or service is attempting to bypass the firewall using a disallowed protocol on an allowed port, or detect if a protocol is being abused in any harmful way. As of 2012, the so-called next-generation firewall is nothing more than the "wider" or "deeper" inspection at the application layer. For example, the existing deep packet inspection functionality of modern firewalls can be extended to include: Intrusion prevention systems User identity management integration Web application firewall. WAF attacks may be implemented in the tool "WAF Fingerprinting utilizing timing side channels" Firewalls are categorized as network-based or host-based. Network-based firewalls are positioned on the gateway computers of WANs and intranets, they are either software appliances running on general-purpose hardware, or hardware-based firewall computer appliances. Firewall appliances may offer other functionality to the internal network they protect, such as acting as a DHCP or VPN server for that network.
Host-based firewalls are positioned on the network node itself and control network traffic in and out of those machines. The host-based firewall may be a daemon or service as a part of the operating system or an agent application such as endpoint security or protection; each has disadvantages. However, each has a role in layered security. Firewalls vary in type depending on where communication originates, where it is intercepted, the state of communication being traced. Network layer firewalls called packet filters, operate at a low level of the TCP/IP protocol stack, not allowing packets to pass through the firewall unless they match the established rule set; the firewall administrator may define the rules. The term "packet filter" originated in the context of BSD operating systems. Network layer firewalls fall into two sub-categories and stateless. Used packet filters on various versions of Unix are ipfw, NPF, PF, ip
Cybercrime, or computer-oriented crime, is a crime that involves a computer and a network. The computer may have been used in the commission of a crime. Cybercrimes can be defined as: "Offences that are committed against individuals or groups of individuals with a criminal motive to intentionally harm the reputation of the victim or cause physical or mental harm, or loss, to the victim directly or indirectly, using modern telecommunication networks such as Internet and mobile phones". Cybercrime may threaten a nation's security and financial health. Issues surrounding these types of crimes have become high-profile those surrounding hacking, copyright infringement, unwarranted mass-surveillance, child pornography, child grooming. There are problems of privacy when confidential information is intercepted or disclosed, lawfully or otherwise. Debarati Halder and K. Jaishankar further define cybercrime from the perspective of gender and defined'cybercrime against women' as "Crimes targeted against women with a motive to intentionally harm the victim psychologically and physically, using modern telecommunication networks such as internet and mobile phones".
Internationally, both governmental and non-state actors engage in cybercrimes, including espionage, financial theft, other cross-border crimes. Cybercrimes crossing international borders and involving the actions of at least one nation state is sometimes referred to as cyberwarfare. A report, published in 2014, estimated that the annual damage to the global economy was $445 billion. $1.5 billion was lost in 2012 to online credit and debit card fraud in the US. In 2018, a study by Center for Strategic and International Studies, in partnership with McAfee, concludes that close to $600 billion, nearly one percent of global GDP, is lost to cybercrime each year. Computer crime encompasses a broad range of activities. Computer fraud is any dishonest misrepresentation of fact intended to let another to do or refrain from doing something which causes loss. In this context, the fraud will result in obtaining a benefit by: Altering in an unauthorized way; this requires little technical expertise and is common form of theft by employees altering the data before entry or entering false data, or by entering unauthorized instructions or using unauthorized processes.
This is difficult to detect. These types of crime result in the loss of private information or monetary information. Government officials and information technology security specialists have documented a significant increase in Internet problems and server scans since early 2001, but there is a growing concern among government agencies such as the Federal Bureau of Investigations and the Central Intelligence Agency that such intrusions are part of an organized effort by cyberterrorists, foreign intelligence services, or other groups to map potential security holes in critical systems. A cyberterrorist is someone who intimidates or coerces a government or an organization to advance his or her political or social objectives by launching a computer-based attack against computers, networks, or the information stored on them. Cyberterrorism in general can be defined as an act of terrorism committed through the use of cyberspace or computer resources; as such, a simple propaganda piece in the Internet that there will be bomb attacks during the holidays can be considered cyberterrorism.
There are hacking activities directed towards individuals, organized by groups within networks, tending to cause fear among people, demonstrate power, collecting information relevant for ruining peoples' lives, blackmailing etc. Cyberextortion occurs when a website, e-mail server, or computer system is subjected to or threatened with repeated denial of service or other attacks by malicious hackers; these hackers demand money in return for promising to stop the attacks and to offer "protection". According to the Federal Bureau of Investigation, cybercrime extortionists are attacking corporate websites and networks, crippling their ability to operate and demanding payments to restore their service. More than 20 cases are reported each month to the FBI and many go unreported in order to keep the victim's name out of the public domain. Perpetrators use a distributed denial-of-service attack. However, other cyberextortion techniques exist such as doxing bug poaching. An example of cyberextortion was the attack on Sony Pictures of 2014.
The U. S. Department of Defense notes that the cyberspace has emerged as a national-level concern through several recent events of geostrategic significance. Among those are included, the attack on Estonia's infrastructure in 2007 by Russian hackers. "In August 2008, Russia again conducted cyberattacks, this time in a coordinated and synchronized kinetic and non-kinetic campaign against the country of Georgia. The December 2015 Ukraine power grid cyberattack has been attributed to Russia and is considered the first successful cyberattack on a power grid. Fearing that such attacks may become the norm in future warfare among nation-states, the concept of cyberspace operations impacts and will be adapted by warfighting military commanders in the future; these crimes are committed by a selected group of criminals. Unlike crimes using the computer as a tool, these crimes require t
Internet service provider
An Internet service provider is an organization that provides services for accessing, using, or participating in the Internet. Internet service providers may be organized in various forms, such as commercial, community-owned, non-profit, or otherwise owned. Internet services provided by ISPs include Internet access, Internet transit, domain name registration, web hosting, Usenet service, colocation; the Internet was developed as a network between government research laboratories and participating departments of universities. Other companies and organizations joined by direct connection to the backbone, or by arrangements through other connected companies, sometime using dialup tools such as UUCP. By the late 1980s, a process was set in place towards commercial use of the Internet; the remaining restrictions were removed by 1991, shortly after the introduction of the World Wide Web. During the 1980s, online service providers such as CompuServe and America On Line began to offer limited capabilities to access the Internet, such as e-mail interchange, but full access to the Internet was not available to the general public.
In 1989, the first Internet service providers, companies offering the public direct access to the Internet for a monthly fee, were established in Australia and the United States. In Brookline, The World became the first commercial ISP in the US, its first customer was served in November 1989. These companies offered dial-up connections, using the public telephone network to provide last-mile connections to their customers; the barriers to entry for dial-up ISPs were low and many providers emerged. However, cable television companies and the telephone carriers had wired connections to their customers and could offer Internet connections at much higher speeds than dial-up using broadband technology such as cable modems and digital subscriber line; as a result, these companies became the dominant ISPs in their service areas, what was once a competitive ISP market became a monopoly or duopoly in countries with a commercial telecommunications market, such as the United States. On 23 April 2014, the U.
S. Federal Communications Commission was reported to be considering a new rule that will permit ISPs to offer content providers a faster track to send content, thus reversing their earlier net neutrality position. A possible solution to net neutrality concerns may be municipal broadband, according to Professor Susan Crawford, a legal and technology expert at Harvard Law School. On 15 May 2014, the FCC decided to consider two options regarding Internet services: first, permit fast and slow broadband lanes, thereby compromising net neutrality. On 10 November 2014, President Barack Obama recommended that the FCC reclassify broadband Internet service as a telecommunications service in order to preserve net neutrality. On 16 January 2015, Republicans presented legislation, in the form of a U. S. Congress H. R. discussion draft bill, that makes concessions to net neutrality but prohibits the FCC from accomplishing the goal or enacting any further regulation affecting Internet service providers. On 31 January 2015, AP News reported that the FCC will present the notion of applying Title II of the Communications Act of 1934 to the Internet in a vote expected on 26 February 2015.
Adoption of this notion would reclassify Internet service from one of information to one of the telecommunications and, according to Tom Wheeler, chairman of the FCC, ensure net neutrality. The FCC is expected to enforce net neutrality in its vote, according to The New York Times. On 26 February 2015, the FCC ruled in favor of net neutrality by adopting Title II of the Communications Act of 1934 and Section 706 in the Telecommunications Act of 1996 to the Internet; the FCC Chairman, Tom Wheeler, commented, "This is no more a plan to regulate the Internet than the First Amendment is a plan to regulate free speech. They both stand for the same concept." On 12 March 2015, the FCC released the specific details of the net neutrality rules. On 13 April 2015, the FCC published the final rule on its new "Net Neutrality" regulations; these rules went into effect on 12 June 2015. Upon becoming FCC chairman in April 2017, Ajit Pai proposed an end to net neutrality, awaiting votes from the commission. On 21 November 2017, Pai announced that a vote will be held by FCC members on 14 December on whether to repeal the policy.
On 11 June 2018, the repeal of the FCC's network neutrality rules took effect. Access provider ISPs provide Internet access, employing a range of technologies to connect users to their network. Available technologies have ranged from computer modems with acoustic couplers to telephone lines, to television cable, Wi-Fi, fiber optics. For users and small businesses, traditional options include copper wires to provide dial-up, DSL asymmetric digital subscriber line, cable modem or Integrated Services Digital Network. Using fiber-optics to end users is called Fiber To The Home or similar names. For customers with more demanding requirements can use higher-speed DSL, metropolitan Ethernet, gigabit Ethernet, Frame Relay, ISDN Primary Rate Interface, ATM and synchronous optical networking. Wireless access is another option, including satellite Internet access. A mailbox provider is an organization that provides services for hosting electronic mail domains with access to storage for mail boxes
A computer network is a digital telecommunications network which allows nodes to share resources. In computer networks, computing devices exchange data with each other using connections between nodes; these data links are established over cable media such as wires or optic cables, or wireless media such as Wi-Fi. Network computer devices that originate and terminate the data are called network nodes. Nodes are identified by network addresses, can include hosts such as personal computers and servers, as well as networking hardware such as routers and switches. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other. In most cases, application-specific communications protocols are layered over other more general communications protocols; this formidable collection of information technology requires skilled network management to keep it all running reliably. Computer networks support an enormous number of applications and services such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers and fax machines, use of email and instant messaging applications as well as many others.
Computer networks differ in the transmission medium used to carry their signals, communications protocols to organize network traffic, the network's size, traffic control mechanism and organizational intent. The best-known computer network is the Internet; the chronology of significant computer-network developments includes: In the late 1950s, early networks of computers included the U. S. military radar system Semi-Automatic Ground Environment. In 1959, Anatolii Ivanovich Kitov proposed to the Central Committee of the Communist Party of the Soviet Union a detailed plan for the re-organisation of the control of the Soviet armed forces and of the Soviet economy on the basis of a network of computing centres, the OGAS. In 1960, the commercial airline reservation system semi-automatic business research environment went online with two connected mainframes. In 1963, J. C. R. Licklider sent a memorandum to office colleagues discussing the concept of the "Intergalactic Computer Network", a computer network intended to allow general communications among computer users.
In 1964, researchers at Dartmouth College developed the Dartmouth Time Sharing System for distributed users of large computer systems. The same year, at Massachusetts Institute of Technology, a research group supported by General Electric and Bell Labs used a computer to route and manage telephone connections. Throughout the 1960s, Paul Baran and Donald Davies independently developed the concept of packet switching to transfer information between computers over a network. Davies pioneered the implementation of the concept with the NPL network, a local area network at the National Physical Laboratory using a line speed of 768 kbit/s. In 1965, Western Electric introduced the first used telephone switch that implemented true computer control. In 1966, Thomas Marill and Lawrence G. Roberts published a paper on an experimental wide area network for computer time sharing. In 1969, the first four nodes of the ARPANET were connected using 50 kbit/s circuits between the University of California at Los Angeles, the Stanford Research Institute, the University of California at Santa Barbara, the University of Utah.
Leonard Kleinrock carried out theoretical work to model the performance of packet-switched networks, which underpinned the development of the ARPANET. His theoretical work on hierarchical routing in the late 1970s with student Farouk Kamoun remains critical to the operation of the Internet today. In 1972, commercial services using X.25 were deployed, used as an underlying infrastructure for expanding TCP/IP networks. In 1973, the French CYCLADES network was the first to make the hosts responsible for the reliable delivery of data, rather than this being a centralized service of the network itself. In 1973, Robert Metcalfe wrote a formal memo at Xerox PARC describing Ethernet, a networking system, based on the Aloha network, developed in the 1960s by Norman Abramson and colleagues at the University of Hawaii. In July 1976, Robert Metcalfe and David Boggs published their paper "Ethernet: Distributed Packet Switching for Local Computer Networks" and collaborated on several patents received in 1977 and 1978.
In 1979, Robert Metcalfe pursued making Ethernet an open standard. In 1976, John Murphy of Datapoint Corporation created ARCNET, a token-passing network first used to share storage devices. In 1995, the transmission speed capacity for Ethernet increased from 10 Mbit/s to 100 Mbit/s. By 1998, Ethernet supported transmission speeds of a Gigabit. Subsequently, higher speeds of up to 400 Gbit/s were added; the ability of Ethernet to scale is a contributing factor to its continued use. Computer networking may be considered a branch of electrical engineering, electronics engineering, telecommunications, computer science, information technology or computer engineering, since it relies upon the theoretical and practical application of the related disciplines. A computer network facilitates interpersonal communications allowing users to communicate efficiently and via various means: email, instant messaging, online chat, video telephone calls, video conferencing. A network allows sharing of computing resources.
Users may access and use resources provided by devices on the network, such as printing a document on a shared network printer or use of a shared storage device. A network allows sharing of files, and