White list
Encyclopedia
Whitelist is a term used to describe a list or register of entities
that, for one reason or another, are being provided a particular privilege, service, mobility, access or recognition. As a verb, to whitelist can mean to authorize access or grant membership. Conversely, blacklist
is a term used to describe a list or compilation that identifies entities that are denied, unrecognised, or ostracised.
whitelist is a list of contacts that the user deems are acceptable to receive email from and should not be sent to the trash folder.
Spam filters that come with e-mail client
s have both whitelists and blacklists of senders and keywords to look for in e-mails. If a spam filter keeps a whitelist, mail from the listed e-mail address
es, domains
, and/or IP address
will always be allowed.
Some internet service provider
s have whitelists that they use to filter e-mail to be delivered to their customers. ISPs receive requests from legitimate companies to add them to the ISP whitelist of companies. Companies either pay for a time period to be allowed to e-mail their customers or the companies pay per complaint received by the ISP from their customers. These payments per complaint increase incrementally; i.e., the first 10 complaints are $10 each, then the next 10 are $20 each. These funds are then used by the ISPs to fund anti-spam programs to prevent unwanted e-mail.
If a whitelist is exclusive, only e-mail from those on the whitelist will get through. If it is not exclusive, it prevents e-mail from being deleted or sent to the junk mail folder by the spam filter. Usually, only end-users would set a spam filter to delete all e-mails from sources not on the whitelist, not internet service providers or e-mail services.
Using whitelists and blacklists can assist in blocking unwanted messages and allowing wanted messages to get through, but they are not perfect. E-mail whitelists are used to reduce the incidence of false positives
, often based on the assumption that most legitimate mail will be from a relatively small and fixed set of senders. To block a high percentage of spam, e-mail filters have to be continuously updated as e-mail spam senders create new email addresses to e-mail from or new keywords to use in their e-mail which allows the e-mail to slip through.
allows someone to bypass spam filters when sending e-mail
messages to its subscribers, in return for a pre-paid fee, either an annual fee or a per-message fee. A sender can then be more confident that his messages have reached their recipients without being blocked, or having links or images stripped out of them, by spam filters. The purpose of commercial whitelists is to allow companies to reliably reach their customers by e-mail.
Commercial providers include GoodMailSystems's Certified Email, Return Path Certification, eco's Certified Senders Alliance
, and the Spamhaus Whitelist.
(LAN) security. Many network admins setup MAC address
whitelists or a MAC address filter to control who is on their networks. This is used when encryption is not a practical solution or in tandem with encryption. However, it's sometimes ineffective because a MAC address can be faked
.
Some firewalls can be configured to only allow data-traffic from/ to certain (ranges of) IP-addresses.
These products may provide administrative control over program whitelists in addition to preventing introduction of new malware, but they cannot stop exploitation of existing processes in order to gain root (and therefore bypass/disable the whitelisting application.
Among Unix Operating system variants, HP-UX has introduced a feature called "HP-UX Whitelisting" on 11iv3 version. HP-UX Whitelisting (WLI) offers file and system resource protection based on RSA encryption technology. WLI is complementary to the traditional UNIX discretionary access controls (DAC) based on user, group, and file permissions. The more granular DAC access control list (ACL) permissions available on VxFS and HFS file systems are likewise not affected.
Entity
An entity is something that has a distinct, separate existence, although it need not be a material existence. In particular, abstractions and legal fictions are usually regarded as entities. In general, there is also no presumption that an entity is animate.An entity could be viewed as a set...
that, for one reason or another, are being provided a particular privilege, service, mobility, access or recognition. As a verb, to whitelist can mean to authorize access or grant membership. Conversely, blacklist
Blacklist
A blacklist is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, mobility, access or recognition. As a verb, to blacklist can mean to deny someone work in a particular field, or to ostracize a person from a certain social circle...
is a term used to describe a list or compilation that identifies entities that are denied, unrecognised, or ostracised.
Email whitelists
An e-mailE-mail
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
whitelist is a list of contacts that the user deems are acceptable to receive email from and should not be sent to the trash folder.
Spam filters that come with e-mail client
E-mail client
An email client, email reader, or more formally mail user agent , is a computer program used to manage a user's email.The term can refer to any system capable of accessing the user's email mailbox, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal...
s have both whitelists and blacklists of senders and keywords to look for in e-mails. If a spam filter keeps a whitelist, mail from the listed e-mail address
E-mail address
An email address identifies an email box to which email messages are delivered. An example format of an email address is lewis@example.net which is read as lewis at example dot net...
es, domains
Domain name
A domain name is an identification string that defines a realm of administrative autonomy, authority, or control in the Internet. Domain names are formed by the rules and procedures of the Domain Name System ....
, and/or IP address
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
will always be allowed.
Some internet service provider
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
s have whitelists that they use to filter e-mail to be delivered to their customers. ISPs receive requests from legitimate companies to add them to the ISP whitelist of companies. Companies either pay for a time period to be allowed to e-mail their customers or the companies pay per complaint received by the ISP from their customers. These payments per complaint increase incrementally; i.e., the first 10 complaints are $10 each, then the next 10 are $20 each. These funds are then used by the ISPs to fund anti-spam programs to prevent unwanted e-mail.
If a whitelist is exclusive, only e-mail from those on the whitelist will get through. If it is not exclusive, it prevents e-mail from being deleted or sent to the junk mail folder by the spam filter. Usually, only end-users would set a spam filter to delete all e-mails from sources not on the whitelist, not internet service providers or e-mail services.
Using whitelists and blacklists can assist in blocking unwanted messages and allowing wanted messages to get through, but they are not perfect. E-mail whitelists are used to reduce the incidence of false positives
Type I and type II errors
In statistical test theory the notion of statistical error is an integral part of hypothesis testing. The test requires an unambiguous statement of a null hypothesis, which usually corresponds to a default "state of nature", for example "this person is healthy", "this accused is not guilty" or...
, often based on the assumption that most legitimate mail will be from a relatively small and fixed set of senders. To block a high percentage of spam, e-mail filters have to be continuously updated as e-mail spam senders create new email addresses to e-mail from or new keywords to use in their e-mail which allows the e-mail to slip through.
Non-commercial whitelists
Non-commercial whitelists are operated by various non-profit organisations, ISPs and other entities interested in blocking spam. Rather than paying fees the sender must pass a series of tests; for example, his email server must not be an open relay and have a Static IP address. The operator of the whitelist may remove a server from the list if complaints are received.Commercial whitelists
Commercial whitelists are a system by which an internet service providerInternet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
allows someone to bypass spam filters when sending e-mail
E-mail
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
messages to its subscribers, in return for a pre-paid fee, either an annual fee or a per-message fee. A sender can then be more confident that his messages have reached their recipients without being blocked, or having links or images stripped out of them, by spam filters. The purpose of commercial whitelists is to allow companies to reliably reach their customers by e-mail.
Commercial providers include GoodMailSystems's Certified Email, Return Path Certification, eco's Certified Senders Alliance
Certified Senders Alliance
The Certified Senders Alliance - initiated by eco and the German Direct Marketing Association - constitutes the central German whitelist since 2005.The CSA whitelist is a positive list for email bulk senders...
, and the Spamhaus Whitelist.
LAN whitelists
Another use for whitelists is local area networkLocal area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
(LAN) security. Many network admins setup MAC address
MAC address
A Media Access Control address is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet...
whitelists or a MAC address filter to control who is on their networks. This is used when encryption is not a practical solution or in tandem with encryption. However, it's sometimes ineffective because a MAC address can be faked
MAC spoofing
MAC spoofing is a technique for changing a factory-assigned Media Access Control address of a network interface on a networked device.- Motivation :...
.
Some firewalls can be configured to only allow data-traffic from/ to certain (ranges of) IP-addresses.
Program whitelists
If an organization keeps a whitelist of software, only titles on the list will be accepted for use. The benefits of whitelisting in this instance are that the school administration can ensure itself that students will not be able to download and/or use programs that have not been deemed appropriate for use.Application whitelists
An emerging approach in combating viruses and malware is to whitelist software which is considered safe to run, blocking all others. Some deem this as superior to the standard signature-based, anti-virus approach of blocking/removing known harmful software (essentially blacklisting), as the standard approach generally means that exploits are already in the wild.These products may provide administrative control over program whitelists in addition to preventing introduction of new malware, but they cannot stop exploitation of existing processes in order to gain root (and therefore bypass/disable the whitelisting application.
Among Unix Operating system variants, HP-UX has introduced a feature called "HP-UX Whitelisting" on 11iv3 version. HP-UX Whitelisting (WLI) offers file and system resource protection based on RSA encryption technology. WLI is complementary to the traditional UNIX discretionary access controls (DAC) based on user, group, and file permissions. The more granular DAC access control list (ACL) permissions available on VxFS and HFS file systems are likewise not affected.