(An Imperial Code in Rome, 1543)

This article presents the analysis of an encrypted code related to the imperial secret communication in Rome during the 1940s of the 16th century. The study employs a mixed methodology based on the discipline of philological editing combined with basic notions of cryptography. The research is not only limited to the study of the letters in which the encryption was used, but also provides a detailed analysis of the encrypted table used to compose the secret message of the letters. In addition to the description, we also offer the reconstruction of the cipher's vocabulary, originally employed in the main corpus.