Autofirma

Autofirma is a desktop application developed by the Spanish Government to facilitate the electronic signing of documents. It functions as a client-side tool that integrates with web browsers to perform cryptographic operations on local files. Users can select documents from their local storage, apply digital signatures using installed certificates, and transmit the signed output to administrative portals. The software is designed to handle various document formats commonly used in public administration workflows.

Because it operates as a local service, the application requires a compatible browser environment to bridge the communication between the web interface and the local file system. It supports standard X.509 digital certificates stored in the operating system's certificate store or on external hardware tokens. The application is primarily intended for interaction with Spanish public administration services, and its functionality is constrained by the specific requirements of those electronic procedures.