*Basic

Ciphertext, or encrypted text, is a series of randomized letters and numbers which humans cannot make sense of. An encryption algorithm takes a plaintext message, runs the algorithm on the plain text, and produces ciphertext.[1]

**Intermediate

The most simple example of ciphertext is the Caesar Cipher we described before. That involves the substitution of a letter in plain text for a letter a certain number of places down the alphabet. So a shift of one would mean A becoming B and B becoming C etc.[2] “Cipher” is the algorithm or process used to encrypt the data. “Encryption” is the process of converting the data using the cipher.[3] Caesar ciphers are not generally used as a standalone encryption technique because they are easy to crack. Many Caesar ciphers can be cracked using brute force. Modern ciphers are more secure and are designed to withstand a wide range of attacks.[4]

***Advanced

Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Cryptanalysis is also referred to as code breaking.[5]

Sources

[1] Editors. Plaintext | Ciphertext. Encryption Consulting. Encryptionconsulting.com
[2] Editors. What is Ciphertext? What Is. Whatis.com
[3] Editors. What is the difference between “cipher” and “encryption”? Stack Exchange. Security.stackexchange.com
[4] Editors. Ciphertext. Wikipedia. en.wikipedia.org
[5] Editors. Cryptanalysis. OWASP Foundation. OWASP.org