A final farewell to ClientLogin, OAuth 1.0 (3LO), AuthSub, and OpenID 2.0

Google has announced the end of support for legacy authentication protocols including ClientLogin, OAuth 1.0 (3LO), AuthSub, and OpenID 2.0, initiating a shutdown process that requires users to migrate to OAuth 2.0 or OpenID Connect. The transition is essential as attempts to use the deprecated services will fail, prompting users to adopt the newer, more secure protocols which are also easier for developers to integrate. Google Sign-in, which is based on OAuth 2.0 and OpenID Connect, offers a streamlined interface for authentication and authorization across web, Android, and iOS platforms. The move underscores Google's focus on modern open standards to enhance account security and improve developer experience.