Keylogging

Keylogging, or keystroke logging, refers to the practice of recording the keys pressed on a keyboard. Keystrokes can reveal passwords, messages, search queries, and other sensitive input. Keyloggers come in software forms that run on a device and in hardware forms that are attached between a keyboard and a computer. Software variants may monitor input at various levels of the operating system, while hardware variants capture signals directly from the keyboard.

Legitimate applications include parental control, enterprise monitoring with explicit consent, and assistive technologies that aid certain users. In all cases, monitoring should comply with applicable laws, contracts, and privacy policies, and workers or users should be informed when monitoring occurs.

Malicious keylogging is a common technique in cybercrime, used to harvest credentials, financial information, or other confidential data. It raises substantial privacy concerns and can enable broader attacks when combined with other malware or social engineering.

Prevention and detection rely on a layered approach: up-to-date security software, system integrity monitoring, application whitelisting, encryption of sensitive data, and strong authentication. Physical security and device control help guard against hardware keyloggers. Organizations should implement clear policies, user education, and regular auditing to reduce risk.

History: Early keyloggers emerged with the growth of computer networks and spyware; today both software and hardware variants exist. For further information, see topics such as spyware, endpoint security, and data protection.