Visualization of cryptographic protocols with GRACE

In this paper we present GRACE (graphical representation and animation for cryptography education), a Java-based educational tool that can be used to help in teaching and understanding of cryptographic protocols. The tool adopts an active learning model that engages the learner by asking him to describe, in an exemplification of a real-world scenario, cryptographic protocols using simple primitives whose effects are visualized by means of animated sequences. To this end, the GRACE interface offers the learner the choice of several cryptographic and non-cryptographic related operations with their respective visualizations. By executing a series of these operations in the proper order, a teacher is able to provide a visual introductory description of several protocols. Moreover, since some of the cryptographic operations are not just simulated but concretely implemented, it can be used by students to see which elaborations are performed by each operation of a cryptographic protocol, and their effects on the represented scenario. GRACE comes equipped with the implementation of several cryptographic primitives and cryptosystems. Additional primitives and cryptosystems can easily be plugged in the system. Visualizations prepared with GRACE can be edited, navigated and saved in a file for playback. We also present the results of an experimental lesson taught in the Security on Communication Networks undergraduate course at the University of Salerno during the fall 2004 semester using GRACE.