研究成果

Shannon was the first to introduce the concept of information-theoretic security, providing a mathematical formulation of security against attackers with unbounded computational power. He concluded that statistical independence is fundamental to defining security. Later, the notion of computational security was proposed, which guarantees protection only against computationally bounded adversaries. This notion was formalized in several ways distinct from Shannon's definition, including semantic security and indistinguishability. In this invited paper, we revisit Shannon's original idea and discuss why he defined information-theoretic security in terms of statistical independence. Furthermore, we explain how this concept evolved into modern formulations that naturally connect to computational security, offering a unified perspective on both paradigms.