Bulgarian medieval cryptography

Bulgarian medieval cryptography is hidden, encrypted writing of certain texts in the Middle Ages. It dates from the 11th century. [1]

Bulgarian medieval writers usually write their name and place of writing in secret. Initially, the Glagolitic script was used in Cyrillic monuments as a secret letter. [1]

Some of the most common medieval Bulgarian cryptographic systems are known, which are of Byzantine origin. The most well-known is the interchange of letters whose numeric value is supplemented to 10, 100 and 1000. Only those Cyrillic letters that have Greek correspondences are included in this system, and the letters by Titlo (5); by Titlo (50) and by Titlo (500) or replace with each other. This mysterious system also has a complicated variant, in which an alphabetic character is represented by several letters, the sum of the numerical values of which is equal to the numerical value of the replaced letter. [1]

Other mysterious systems are the interchange of consonant letters, arranged in two lines; the microscopic letter; the mirror letter and the monogram. [1]

There are no specialized studies in the field of Bulgarian medieval cryptography with a view to distribution in time and territorial scope. [1]