A method, system, and computer program for securely sharing log-in credentials among trusted browser-based applications. Credentials for a user are automatically shared only among a restricted and authorized set of trusted applications, without requiring the application developer to write code to manage the credentials. A single log-in is used to obtain the user credentials for a particular codebase, and the credentials are then reused for applications in that codebase. The Java sandbox concept is exploited to provide this restricted sharing, such that the credentials are stored in the shared static data area associated with the server and codebase from which the set of trusted applications was downloaded.