Abstract: The AVISPA Tool for the Automated Validation of Internet Security Protocols and Applications Alessandro Armando and David Basin and Yohan Boichut and Yannick Chevalier and Luca Compagna and Jorge Cuellar and Paul Hankes Drielsma and Pierre-Cyrille Heám and Olga Kouchnarenko and Jacopo Mantovani and Sebastian Mödersheim and von Oheimb, David and Michael Rusinowitch and Judson Santiago and Mathieu Turuani and Luca Viganò and Laurent Vigneron AVISPA is a push-button tool for the automated validation of Internet security-sensitive protocols and applications. It provides a modular and expressive formal language for specifying protocols and their security properties, and integrates different back-ends that implement a variety of state-of-the-art automatic analysis techniques. To the best of our knowledge, no other tool exhibits the same level of scope and robustness while enjoying the same performance and scalability.