Peter, a security professional, was hired by an organization and was instructed to secure the application and its content from unauthorized access. In this process, Peter implemented a public- key cry

Peter, a security professional, was hired by an organization and was instructed to secure the application and its content from unauthorized access. In this process, Peter implemented a public- key cryptosystem that uses modular arithmetic and elementary number theory for Internet encryption and user authentication. Which of the following algorithms was employed by Peter in the above scenario?