cyclical-shift substitution cipher

The term "cyclical-shift substitution cipher" refers to a basic method in cryptology, the science of secure communication. This type of cipher works by replacing each letter in a message with another letter a fixed number of positions away in the alphabet. A well-known example is the Caesar cipher, where Julius Caesar famously shifted letters by three positions (A became D, B became E, and so on). While simple to implement, these types of ciphers, also known as monoalphabetic substitution ciphers, are not secure because the pattern of letter frequencies in the original message is preserved in the coded message, making them relatively easy to break through cryptanalysis.123