Classical Cryptanalysis refers to the study and practice of breaking encryption methods that were used before the digital age. It primarily focuses on techniques to decipher messages without access to the key, often relying on patterns, frequency analysis, and known plaintext attacks. Historical ciphers, such as the Caesar cipher and Vigenère cipher, are common targets for classical cryptanalysis. This field played a crucial role in the development of modern cryptography. By understanding the weaknesses in classical systems, cryptographers have been able to create more secure algorithms. Techniques from classical cryptanalysis laid the groundwork for contemporary methods used in computer security today.