Cryptology of the long eighteenth century became an explicit discipline of secrecy. Theorized in pedagogical texts that reached wide audiences, multimodal methods of secret writing during the period in England promoted algorithmic literacy, introducing reading practices like discernment, separation, recombination, and pattern recognition. In composition, secret writing manipulated materials and inspired new technologies in instrumentation, computation, word processing, and storage. Cryptology also revealed the visual habits of print and the observational consequences of increasing standardization in writing, challenging the relationship between print and script. Secret writing served not only military strategists and politicians; it gained popularity with everyday readers as a pleasurable cognitive activity for personal improvement and as an alternative way of thinking about secrecy and literacy.