This paper aims to analyze the feasibility of implementing a didactic sequence for the teaching and learning process of Combinatorial Analysis, using Cryptography as an educational tool for High School. For this, a project was applied in the second semester of 2017, lasting 26 class hours, in a class of the 2nd year of high school, composed of 22 students from a public school in the interior of São Paulo State - Brazil. This teaching proposal appropriated Didactic Engineering as a Research methodology, which enabled the development of a didactic sequence. This in turn was divided into six steps, which approached counting techniques, without the use of formulas, through the encryption of binary numbers, Caesar's code and the encryption present in the film: The Da Vinci Code. This study was exposed by students participating in the project at the school's Science Fair. In order to analyze the learning evolution of the participating students, a pre-test and a post-test were applied, which presented a satisfactory evolution in the students learning. It was also possible to realize, during the project application, the improvement and development of the skills of: teamwork, self-confidence, oratory, time management and autonomy in the pursuit of knowledge.