Whitelist

A whitelist is a list of email addresses, IP addresses, or applications that are deemed safe and allowed to run or be seen on a device or network. Where blacklists only block items on the list, whitelists are similar to a VIP list and only allow entry to the items on that list. They are both often used as cybersecurity measures.

Common uses of whitelisting

  • Email: Perhaps the most popular use for whitelisting is for blocking spam and phishing attempts from an email inbox by creating a safe senders list. This ensures that emails from senders you want to see don t end up in a spam folder, and spam emails don t show up in your inbox.
  • IP Addresses: IP whitelisting is used to grant network access only to certain IP addresses. While this has been used as a security measure, it does have its drawbacks. First of all, IP addresses are not constant and can change often. Second, IP addresses can be spoofed using a VPN and can cause your network to become less secure.
  • Applications: Application whitelisting refers to whitelisting only trusted and secure applications on a device. The ability to whitelist applications is usually added onto an OS. This practice is often used on employee computers that are monitored by an administrator to keep the network safe and employees from downloading apps that might inhibit productivity. Application whitelisting also poses the risk of an attacker replacing a whitelisted application with a malicious one by ensuring they have the same specifications. You can take additional security steps by applying cryptographic hashing.

Note: In recent years, prominent members of the computing industry have started to shift away from using the terms whitelist and blacklist because of their negative connotation and have instead shifted to allowlist/denylist or passlist/blocklist.

Vangie Beal
Vangie Beal is a freelance business and technology writer covering Internet technologies and online business since the late '90s.

Top Articles

List of Windows Operating System Versions & History [In Order]

The Windows operating system (Windows OS) refers to a family of operating systems developed by Microsoft Corporation. We look at the history of Windows...

How to Create a Website Shortcut on Your Desktop

Website Shortcut on Your Desktop reviewed by Web Webster   This Webopedia guide will show you how to create a website shortcut on your desktop using...

What are the Five Generations of Computers? (1st to 5th)

Reviewed by Web Webster Each generation of computer has brought significant advances in speed and power to computing tasks. Learn about each of the...

Hotmail [Outlook] Email Accounts

Launched in 1996, Hotmail was one of the first public webmail services that could be accessed from any web browser. At its...

What Is Training Data?

Training data is used to increase the accuracy of machine learning algorithms with...

GRC

Governance, risk, and compliance (GRC) refers to a company’s strategy for managing the...

Roll Your Own Crypto...

Cryptocurrency has quickly become a digital...