Acipher is the technology of encrypting text for it to be readable andwith meaning. Cipher also refers to the encrypted text message(Ortmeier,2013).Ciphers works by realigning the alphabets or manipulating text in aconsistent pattern. For instance, A to represent D, B t represent E,C to represent F, and so on. In other words, a cipher is whereby acipher symbol or letter replaces every letter in a message. This isunlike to the code whereby code word or symbol replaces every word ina message. Examples of ciphers include ROT1, transposition, andPublic-key cryptography.
ROT1 cipher is commonly familiar among the children than adults.According to Ortmeier(2013),ROT1 means to rotate letter forward throughout the alphabets. Its keysimple because each alphabetical letter is replaced with followingletter. For instance, letter B replaces letter A, letter C replacesletter B, and so on. This cipher is fit for children because it iseasy to understand, as well as to use. This cipher is only applicableto make fun but not for serious use.
Transpositioncipher involves rearranging letters according to predetermined key orrule. That is, all letters in the word may be written backward orswapped letters in a word. During the American Civil War and theFirst World War, transposition cipher was common to send sensitivemessages (McCrie,2006).However, transposition cipher uses complex rule to rearrange lettersmaking it hard to crack the message.
Public-keycryptography is the most crucial modern cipher. The cipher hasseveral variants with two keys: public and private (McCrie,2006).The public key is available to the public while the private key is aspecial key that is only divisible by one and itself. Amultiplication of two private numbers gives a public number. A publickey can encipher a message but cannot decipher without private key.
McCrie,R. D. (2006). Securityoperations management.Burlington: Elsevier.
Ortmeier,P.J. (2013).Introduction to security Operations and management (4thed.). Upper Saddle River, NJ: Pearson Education