OATH versus OAuth

May 02, 2023

Similar terms for authentication and authorization – yet very different technologies.

OATH (Open Authentication) and OAuth (Open Authorization) are two different technologies commonly used in web authentication and authorization.

OATH is an open standard for strong authentication that enables the use of one-time password (OTP) technologies. It defines a set of algorithms and protocols for creating and verifying one-time passwords that can be used on a variety of devices and platforms. OATH is commonly used in two-factor authentication (2FA) to enhance the security of applications and services. See also: https://openauthentication.org/.

OATH OTP (One-Time Password) is a form of two-factor authentication (2FA) that uses a time-based algorithm to generate a unique, one-time code that is used in addition to a traditional username and password to authenticate a user’s identity. This provides an extra layer of security for sensitive accounts or transactions.

The OATH OTP system is based on the Time-Based One-Time Password (TOTP) algorithm, which generates a unique code that changes every 30 or 60 seconds. The user enters the current code, along with their username and password, to authenticate themselves. The system then verifies the code, and if it matches the expected value, the user is granted access. There is also an variant for event-based password generation (HOTP).

OATH OTP is widely used by online services and websites to provide additional security for their users, such as online banking, email services, and other sites that contain sensitive information. It is also used in physical security applications, such as building access control and two-factor authentication for VPNs (Virtual Private Networks).

OAuth (Open Authorization), on the other hand, is an open standard for authorization that allows users to grant third-party access to their resources (e.g., accounts, images, documents) without revealing their credentials. It allows users to authenticate to a service using their existing credentials and then delegate authorization to another service to access their resources. OAuth is commonly used by social networks and other web applications to provide access to their APIs and services, without having to share their username and password. It is used by many online services and applications to allow users to grant access to their data on other platforms or services. See also https://oauth.net/.

In an OAuth system, the user is directed to the authorization server of the service they want to use, where they can grant permission for the third-party application to access their data. The authorization server then generates a unique access token, which is sent to the third-party application. This token allows the application to access the user’s data for a limited time, without having to store or transmit the user’s username and password.

OAuth provides a secure and standardized way for users to grant access to their data to third-party applications, while maintaining control over their personal information. It also enables developers to create applications that can securely access user data from multiple services, without having to store the user’s login credentials.

In summary, OATH focuses on authenticating users, while OAuth focuses on authorizing third-party applications. However, both technologies have their own areas of application and are often used in combination with other technologies to ensure the security and protection of user data and resources.