Token

Token (Computers, Programming, and Cybersecurity)

A token is an authorization credential or a digital object which is used to represent the identity of a user or device. In computer security, tokens are typically used for authentication and verification. Technically speaking, a token is any piece of digital information which can be exchanged between two or more entities in order to validate identity or authorization. In computer programming, tokens are also known as lexemes or symbols, and they may represent literal values, such as numbers or words, or logical expressions which can be combined to form a larger expression.

Tokens come in many different formats, including physical tokens such as a flash drive or USB token, as well as logical tokens such as software tokens. Token-based authorization systems are used in a wide variety of applications, including single sign-on (SSO) services, access control systems, cloud-based systems, and distributed applications. In token generation and validation, the sending or presenting of the token is the authentication phase while the verifying or decrypting of the token is the authorization phase.

The tokens used in computer programming and cybersecurity may also have other specific attributes, such as a validity period and a one-time-use (OTU) value. When a token is validated, it must be associated with a user in order to grant them access to the system. Token-based authorization systems are designed to be secure and resilient against security threats such as credential stuffing, phishing, or unauthorized authentication attempts. Implementations of token-based authorization include OAuth, OpenID Connect, Basic Authentication, and JSON Web Tokens (JWTs).

Token-based authentication systems are widely used in developing applications to securely verify users, and can be used to protect resources from unauthorized access. The proper use of tokens can ensure that only authenticated users with valid authorization credentials can access the system.