Käyttäjätunnistautuminen

Käyttäjätunnistautuminen, commonly referred to as user authentication in English, is the process of verifying the identity of a user attempting to access a system or service. This is a fundamental security mechanism employed across various digital platforms, from websites and applications to operating systems and network devices. The primary goal of authentication is to ensure that only authorized individuals can gain access to specific resources, thereby protecting sensitive data and preventing unauthorized actions.

The most common form of user authentication involves credentials such as a username and a password. The user provides these credentials, and the system compares them against a stored record. If they match, access is granted. However, password-based authentication alone can be vulnerable to various attacks, leading to the development and adoption of more robust methods.

Multi-factor authentication (MFA) is an increasingly prevalent approach that requires users to provide two or more verification factors to gain access. These factors typically fall into three categories: something the user knows (like a password or PIN), something the user has (like a smartphone or a security token), or something the user is (like a fingerprint or facial scan). By requiring multiple factors, MFA significantly enhances security by making it much harder for unauthorized individuals to compromise an account, even if one factor is somehow obtained. Other authentication methods include single sign-on (SSO), biometric authentication, and certificate-based authentication, each offering different levels of security and convenience.