Internet security
Encyclopedia
Internet security is a branch of computer security
specifically related to the Internet
. Its objective is to establish rules and measures to use against attacks over the Internet. The Internet represents an insecure channel for exchanging information leading to a high risk of intrusion
or fraud, such as phishing
. Different methods have been used to protect the transfer of data, including encryption
.
(IP) layer.
The basic components of the IPsec security architecture are described in terms of the following functionalities:
The set of security services provided at the IP layer includes access control, data origin integrity, protection against replays, and confidentiality. The algorithm allows these sets to work independently without affecting other parts of the implementation. The IPsec implementation is operated in a host or security gateway environment giving protection to IP traffic.
(MTA) operating on the mail server. The mail client then provides the sender’s identity to the server. Next, using the mail server commands, the client sends the recipient list to the mail server. The client then supplies the message. Once the mail server receives and processes the message, several events occur: recipient server identification, connection establishment, and message transmission. Using Domain Name System (DNS) services, the sender’s mail server determines the mail server(s) for the recipient(s). Then, the server opens up a connection(s) to the recipient mail server(s) and sends the message employing a process similar to that used by the originating client, delivering the message to the recipient(s).
.
Email messages can be protected by using cryptography in various ways, such as the following:
The first two methods, message signing and message body encryption, are often used together; however, encrypting the transmissions between mail servers is typically used only when two organizations want to protect emails regularly sent between each other. For example, the organizations could establish a virtual private network (VPN) to encrypt the communications between their mail servers over the Internet. Unlike methods that can only encrypt a message body, a VPN can encrypt entire messages, including email header information such as senders, recipients, and subjects. In some cases, organizations may need to protect header information. However, a VPN solution alone cannot provide a message signing mechanism, nor can it provide protection for email messages along the entire route from sender to recipient.
(SMTP) to be sent through the Internet. The server SMTP at the receiver's side receives the NVT ASCII data and delivers it to MIME to be transformed back to the original non-ASCII data.
S/MIME provides a consistent means to securely send and receive MIME data. S/MIME is not only limited to email but can be used with any transport mechanism that carries MIME data, such Hypertext Transfer Protocol (HTTP).
is a cryptography method that uses a secret key
to encrypt a message. This method outputs a MAC value that can be decrypted by the receiver, using the same secret key used by the sender. The Message Authentication Code protects both a message's data integrity
as well as its authenticity
.
(NAT), which can hide the user's IP address from the Internet, effectively protecting all internal information from the Internet.
Such programs are used to detect and usually eliminate viruses; however, it is now common to see security suites, containing also firewalls, anti-spyware, theft protection, and so on to more thoroughly protect users.
Traditionally, a user would pay for antivirus software; however, computer users now can, and do, download from a host of free security applications on the Internet.
site
or service
from functioning efficiently or at all, temporarily or indefinitely.
6, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were commonly exploited due to its former popularity. Now, however, browser choice is more evenly distributed (Internet Explorer at 22.9%, Firefox at 39.7%, Google Chrome
at 30.5%, and so on); vulnerabilities are commonly exploited in many browsers. Apple's web browser, Safari
, is the fourth most popular web browser. Although it is only 4% of the total browser usage, it too has many vulnerabilities.
Computer security
Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...
specifically related to the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. Its objective is to establish rules and measures to use against attacks over the Internet. The Internet represents an insecure channel for exchanging information leading to a high risk of intrusion
Hacker (computer security)
In computer security and everyday language, a hacker is someone who breaks into computers and computer networks. Hackers may be motivated by a multitude of reasons, including profit, protest, or because of the challenge...
or fraud, such as phishing
Phishing
Phishing is a way of attempting to acquire information such as usernames, passwords, and credit card details by masquerading as a trustworthy entity in an electronic communication. Communications purporting to be from popular social web sites, auction sites, online payment processors or IT...
. Different methods have been used to protect the transfer of data, including encryption
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
.
Network layer security
TCP/IP can be made secure with the help of cryptographic methods and protocols that have been developed for securing communications on the Internet. These protocols include SSL and TLS for web traffic, PGP for email, and IPsec for the network layer security.IPsec Protocol
This protocol is designed to protect communication in a secure manner using TCP/IP. It is a set of security extensions developed by IETF, and it provides security and authentication at the IP layer by using cryptography. To protect the content, the data is transformed using encryption techniques. There are two main types of transformation that form the basis of IPsec: the Authentication Header (AH) and Encapsulating Security Payload (ESP). These two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be used alone or in combination to provide the desired set of security services for the Internet ProtocolInternet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
(IP) layer.
The basic components of the IPsec security architecture are described in terms of the following functionalities:
- Security protocols for AH and ESP
- Security association for policy management and traffic processing
- Manual and automatic key management for the internet key exchange (IKE)
- Algorithms for authentication and encryption
The set of security services provided at the IP layer includes access control, data origin integrity, protection against replays, and confidentiality. The algorithm allows these sets to work independently without affecting other parts of the implementation. The IPsec implementation is operated in a host or security gateway environment giving protection to IP traffic.
Background
Email messages are composed, delivered, and stored in a multiple step process, which starts with the message's composition. When the user finishes composing the message and sends it, the message is transformed into a standard format: an RFC 2822 formatted message. Afterwards, the message can be transmitted. Using a network connection, the mail client, referred to as a mail user agent (MUA), connects to a mail transfer agentMail transfer agent
Within Internet message handling services , a message transfer agent or mail transfer agent or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture...
(MTA) operating on the mail server. The mail client then provides the sender’s identity to the server. Next, using the mail server commands, the client sends the recipient list to the mail server. The client then supplies the message. Once the mail server receives and processes the message, several events occur: recipient server identification, connection establishment, and message transmission. Using Domain Name System (DNS) services, the sender’s mail server determines the mail server(s) for the recipient(s). Then, the server opens up a connection(s) to the recipient mail server(s) and sends the message employing a process similar to that used by the originating client, delivering the message to the recipient(s).
Pretty Good Privacy (PGP)
PGP provides confidentiality by encrypting messages to be transmitted or data files to be stored using an encryption algorithm such 3DES or CAST-128CAST-128
in cryptography, CAST-128 is a block cipher used in a number of products, notably as the default cipher in some versions of GPG and PGP. It has also been approved for Canadian government use by the Communications Security Establishment...
.
Email messages can be protected by using cryptography in various ways, such as the following:
- Signing an email message to ensure its integrity and confirm the identity of its sender.
- Encrypting the body of an email message to ensure its confidentiality.
- Encrypting the communications between mail servers to protect the confidentiality of both the message body and message header.
The first two methods, message signing and message body encryption, are often used together; however, encrypting the transmissions between mail servers is typically used only when two organizations want to protect emails regularly sent between each other. For example, the organizations could establish a virtual private network (VPN) to encrypt the communications between their mail servers over the Internet. Unlike methods that can only encrypt a message body, a VPN can encrypt entire messages, including email header information such as senders, recipients, and subjects. In some cases, organizations may need to protect header information. However, a VPN solution alone cannot provide a message signing mechanism, nor can it provide protection for email messages along the entire route from sender to recipient.
Multipurpose Internet Mail Extensions (MIME)
MIME transforms non-ASCII data at the sender's site to Network Virtual Terminal (NVT) ASCII data and delivers it to client's Simple Mail Transfer ProtocolSimple Mail Transfer Protocol
Simple Mail Transfer Protocol is an Internet standard for electronic mail transmission across Internet Protocol networks. SMTP was first defined by RFC 821 , and last updated by RFC 5321 which includes the extended SMTP additions, and is the protocol in widespread use today...
(SMTP) to be sent through the Internet. The server SMTP at the receiver's side receives the NVT ASCII data and delivers it to MIME to be transformed back to the original non-ASCII data.
- Secure/Multipurpose Internet Mail Extensions (S/MIME)
S/MIME provides a consistent means to securely send and receive MIME data. S/MIME is not only limited to email but can be used with any transport mechanism that carries MIME data, such Hypertext Transfer Protocol (HTTP).
Message Authentication Code
A Message Authentication CodeMessage authentication code
In cryptography, a message authentication code is a short piece of information used to authenticate a message.A MAC algorithm, sometimes called a keyed hash function, accepts as input a secret key and an arbitrary-length message to be authenticated, and outputs a MAC...
is a cryptography method that uses a secret key
Key (cryptography)
In cryptography, a key is a piece of information that determines the functional output of a cryptographic algorithm or cipher. Without a key, the algorithm would produce no useful result. In encryption, a key specifies the particular transformation of plaintext into ciphertext, or vice versa...
to encrypt a message. This method outputs a MAC value that can be decrypted by the receiver, using the same secret key used by the sender. The Message Authentication Code protects both a message's data integrity
Data integrity
Data Integrity in its broadest meaning refers to the trustworthiness of system resources over their entire life cycle. In more analytic terms, it is "the representational faithfulness of information to the true state of the object that the information represents, where representational faithfulness...
as well as its authenticity
Authentication
Authentication is the act of confirming the truth of an attribute of a datum or entity...
.
Firewalls
A firewall controls access between networks. It generally consists of gateways and filters which vary from one firewall to another. Firewalls also screen network traffic and are able to block traffic that is dangerous. Firewalls act as the intermediate server between SMTP and HTTP connections.Role of firewalls in Internet security and web security
Firewalls impose restrictions on incoming and outgoing packets to and from private networks. All the traffic, whether incoming or outgoing, must pass through the firewall; only authorized traffic is allowed to pass through it. Firewalls create checkpoints between an internal private network and the public Internet, also known as choke points. Firewalls can create choke points based on IP source and TCP port number. They can also serve as the platform for IPsec. Using tunnel mode capability, firewall can be used to implement VPNs. Firewalls can also limit network exposure by hiding the internal network system and information from the public Internet.Packet filters
Packet filters are one of several different types of firewalls that process network traffic on a packet-by-packet basis. Their main job is to filter traffic from a remote IP host, so a router is needed to connect the internal network to the Internet. The router is known as a screening router, which screens packets leaving and entering the network.Circuit-level gateways
The circuit-level gateway is a proxy server that statically defines what traffic will be allowed. Circuit proxies always forward packets containing a given port number, provided the port number is permitted by the rules set. This gateway operates at the network level of an OSI model. The main advantage of a proxy server is its ability to provide Network Address TranslationNetwork address translation
In computer networking, network address translation is the process of modifying IP address information in IP packet headers while in transit across a traffic routing device....
(NAT), which can hide the user's IP address from the Internet, effectively protecting all internal information from the Internet.
Application-level gateways
An application-level gateway is a proxy server operating at the TCP/IP application level. A packet is forwarded only if a connection is established using a known protocol. Application-level gateways are notable for analyzing entire messages rather than individual packets of data when the data are being sent or received.Malware
Commonly, a computer user can be tricked or forced into downloading software onto a computer that is of malicious intent. Such programs are known as malware and come in many forms, such as viruses, Trojan horses, spyware, and worms. Malicious software is sometimes used to form botnets.Viruses
Viruses are programs that can replicate their structures or effects by infecting other files or structures on a computer. The common use of a virus is to take over a computer to steal data.Trojan horse
A Trojan horse (commonly known as a Trojan) is a general term for malicious software that pretends to be harmless so that a user willingly allows it to be downloaded onto the computer.Spyware
The term spyware refers to programs that surreptitiously monitor activity on a computer system and report that information to others without the user's consent.Worms
Worms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout.Botnet
A botnet is a network of "zombie" computers that have been taken over by a "bot" that performs large-scale malicious acts for the creator of the botnet.Antivirus
Antivirus programs and Internet security programs are useful in protecting a computer or programmable device from malware.Such programs are used to detect and usually eliminate viruses; however, it is now common to see security suites, containing also firewalls, anti-spyware, theft protection, and so on to more thoroughly protect users.
Traditionally, a user would pay for antivirus software; however, computer users now can, and do, download from a host of free security applications on the Internet.
Denial-of-service attack
A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of the concerted efforts of person or persons to prevent an InternetInternet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
site
Website
A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...
or service
Web service
A Web service is a method of communication between two electronic devices over the web.The W3C defines a "Web service" as "a software system designed to support interoperable machine-to-machine interaction over a network". It has an interface described in a machine-processable format...
from functioning efficiently or at all, temporarily or indefinitely.
Browser choice
Web browser statistics tend to affect the amount a Web browser is exploited. For example, Internet ExplorerInternet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
6, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were commonly exploited due to its former popularity. Now, however, browser choice is more evenly distributed (Internet Explorer at 22.9%, Firefox at 39.7%, Google Chrome
Google Chrome
Google Chrome is a web browser developed by Google that uses the WebKit layout engine. It was first released as a beta version for Microsoft Windows on September 2, 2008, and the public stable release was on December 11, 2008. The name is derived from the graphical user interface frame, or...
at 30.5%, and so on); vulnerabilities are commonly exploited in many browsers. Apple's web browser, Safari
Safari (web browser)
Safari is a web browser developed by Apple Inc. and included with the Mac OS X and iOS operating systems. First released as a public beta on January 7, 2003 on the company's Mac OS X operating system, it became Apple's default browser beginning with Mac OS X v10.3 "Panther". Safari is also the...
, is the fourth most popular web browser. Although it is only 4% of the total browser usage, it too has many vulnerabilities.
Buffer overflow attacks
A buffer overflow is an attack that could be used by a cracker to get full system access through various methods by essentially cracking a computer using brute force. Most security applications and suites are incapable of adequate defense against these kinds of attacks.See also
- Computer securityComputer securityComputer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...
- Cyberspace Electronic Security ActCyberspace Electronic Security ActThe Cyberspace Electronic Security Act of 1999 is a bill proposed by the Clinton administration during the 106th United States Congress that enables the government to harvest keys used in encryption. The Cyberspace Electronic Security Act gives law enforcement the ability to gain access to...
(in the US) - Firewalls and Internet SecurityFirewalls and Internet SecurityFirst published in 1994, the book Firewalls and Internet Security: Repelling the Wily Hacker by William R. Cheswick and Steve Bellovin helped define the concept of a network firewall...
(book) - Identity Driven NetworkingIdentity Driven NetworkingIdentity Driven Networking is the process of applying network controls to a network device access based on the identity of an individual or group of individuals responsible to or operating the device...
- Network security policyNetwork security policyA network security policy is a generic document that outlines rules for computer network access, determines how policies are enforced and lays out some of the basic architecture of the company security/ network security environment. The document itself is usually several pages long and written by a...
- Antivirus softwareAntivirus softwareAntivirus or anti-virus software is used to prevent, detect, and remove malware, including but not limited to computer viruses, computer worm, trojan horses, spyware and adware...
- Securelist.com
- Internet safety
- Wikipedia:Personal security practices
External links
- IP Authentication Header
- Encapsulating Security Payload
- Wireless Safety - Up to date info on the latest security threats, top news stories, and step by step tutorials on how to best protect yourself and family or organization.
- Broadband Reports - FAQs and forums on Internet security etc.
- PwdHash - Firefox & IE browser extensions that transparently converts a user's password into a domain-specific password.
- Internet security - by JC & Goio (security programs).
- The Internet and Data Security Guide - A to Z Glossary of terms
- Cybertelecom :: Security - surveying federal Internet security work