The increasing complexity and contentiousness of the cyber domain require a well-educated Navy cyber force to defend its networks and key terrain. This demanding operational environment necessitates efficient and effective cybersecurity training and education, which can be maximized by leveraging newer methods and technologies. Cryptography is an essential element of cybersecurity, and is taught in the Naval Postgraduate School computer science curriculum through various methods, including a lab activity exploring symmetric encryption algorithms to reinforce critical concepts. This lab has heretofore been conducted using an older command line interface CLI style of computer interaction, requiring students to enter long commands into the CLI, which was prone to human error. This tended to shift students focus more on command entry and less on the critical learning objectives of the lab activity. This thesis work has designed, developed, and implemented a web-based graphical user interface GUI application for use in completion of the symmetric cryptography lab activity, to increase learner comprehension and understanding of the fundamentals of encryption. The application was developed using principles of human-computer interaction and design, and was subsequently tested against the legacy system, showing that the GUI application performed equally as well for pedagogical purposes.