Starting fromCryptographic Algorithms
Building a StrongNetwork and Data SecurityBarrier
Nanjing University of Posts and Telecommunications collaborates with Nanjing University of Science and Technology Experimental Primary School
to conduct a series of information education courses
In the digital age, without network security, there is no technological security; without data security, there is no national security. In response to the spirit of the 20th National Congress of the Communist Party of China —promoting the construction of a digital China and strengthening the network and data security defenses, on November 14, 2025, theInformation Management School of Nanjing University sent theInformation Literacy Lecturer Team toNanjing University of Science and Technology Experimental Primary School to bring a fun and mission-driven information literacy class to the children —“Cryptographic Algorithms: Caesar Cipher”.
This popular science activity was conducted with the support of theNational Social Science Fund Major Project“Research on the Theory and Practice of Enhancing National Digital Literacy in the Intelligent Era” (24&ZD180). The course focused on the theme of“National Security: Youth Responsibility”, starting from classical cryptography, combined with interactive games and hands-on practice, guiding students to explore the mysteries of cryptographic technology, feel the important role of algorithms in information protection, and learn how to build a strong network security barrier to safeguard digital sovereignty.
Understanding Encryption: From “Garbage” to “Rules”
At the beginning of the course, lecturer Fan Yitao started with common information transmission methods in students’ daily lives, such as WeChat scanning and express delivery tracking numbers, helping students understand that the development of network and data security permeates all areas of life. He explained the basic concepts of cryptographic algorithms in an easy-to-understand manner, planting the seed of “Digital China construction, security first”.
Subsequently, through a series of interactions with the students, the lecturer helped them realize that encryption is not only a technical means but also a form of thinking training — how to transform information through rules and accurately restore it when needed, laying a solid theoretical foundation for the subsequent practical session.
Interactive Game: I am a Little Cryptographer
The “Encryption and Decryption Game” segment in the class brought the atmosphere to a climax. Students were divided into groups to play the roles of encoders and decoders, experiencing the entire process of information transmission in a tense and fun competition. The students in the audience also actively participated in guessing, creating a lively classroom atmosphere.
After successfully encrypting and transmitting English words in the first two rounds, in the third round, the students responsible for encryption failed to decrypt due to excessive pursuit of encryption, even though the decoders knew the encryption rules, leading to subsequent course content on encryption.
Meanwhile, the unique encryption algorithm created by the second group of students coincided with the Caesar cipher, providing an opportunity for the lecturer to guide the discussion towards the Caesar cipher and the course content on encryption algorithms.
Practical Exercise: Experiencing Cryptographic Algorithms on Trae
Subsequently, the lecturer vividly explained the historical origins of cryptographic algorithms and the Caesar cipher through two videos. Based on theoretical learning, he guided the students to perform practical operations on the Trae platform, allowing them to personally experience the complete process from encryption to decryption and then to cracking.
This “learning by doing” approach made abstract knowledge accessible, allowing students to truly appreciate the significant application value of algorithms in defending digital China and supporting national rejuvenation, embedding the concept of “national security” deeply in their hearts.
Review Q&A: Interactive Knowledge Reinforcement
The course included a Q&A session to help students review what they had learned. Everyone actively thought and spoke up, reinforcing the key points of the class in a relaxed atmosphere, demonstrating good learning outcomes — when asked what the mission of cryptographic algorithms is, the children answered in unison: to protect national data sovereignty and safeguard digital China! Their innocent responses echoed the youthful pledge to “deepen the construction of digital China and strengthen the network and data security defenses”.
Although the course has ended, the exploration has not stopped. The lecturer encouraged students to bring what they learned in class into their lives, trying encryption games with family and friends, and thinking about the similarities and differences in various encryption methods and their security. The cultivation of information literacy is not achieved overnight but relies on continuous curiosity and practice. Algorithms are not out of reach; they are hidden in every instance of information transmission. May this class serve as a window, helping students see a broader digital world and the infinite possibilities of their future with technology.
Deepening the construction of digital China cannot be separated from the next generation’s sensitivity and respect fornetwork and data security. Today’s lesson has planted a seed of “secure and controllable” in their hearts — waiting for it to grow and flourish, it will surely guard national data sovereignty with a self-controllable “Chinese key” and support digital China!
Written by | Qiu Yuchen
Images by | Qiu Yuchen
Design by | Qiu Yuchen
Edited by | Yang Yue, Nie Shenghao
Reviewed by | Geng Yuexi
