With the emerging importance of cybersecurity, it will be beneficial for a wide community to understand some of the fundamental security mechanisms. The RSA algorithm is one of the essential algorithms used in public-key cryptosystems. Understanding the RSA algorithm requires knowledge regarding number theory, modular arithmetic, etc., which is often beyond the knowledge pool of many beginners in cybersecurity. In this work, we provide an intuitive and onion-peeling style introduction to the RSA algorithm, in which we assume that readers will only have a basic background in mathematics and cybersecurity. Started from three essential goals of public-key cryptosystems, we explained step-by-step how the RSA algorithm achieved these goals. We also used a toy example to further help readers to understand the algorithm from a practical perspective.

翻译：随着网络安全重要性的日益凸显，广泛理解基本安全机制将大有裨益。RSA算法是公钥密码体制中使用的核心算法之一。理解RSA算法需要掌握数论、模运算等知识，这往往超出了许多网络安全初学者的知识范围。在本研究中，我们采用直观的"剥洋葱"式方法介绍RSA算法，假设读者仅具备数学和网络安全的基础背景。从公钥密码体制的三个基本目标出发，我们逐步阐释了RSA算法如何实现这些目标。同时，我们通过一个简易实例进一步帮助读者从实践角度理解该算法。