What is the primary focus of cryptanalysis?

The primary focus of cryptanalysis is on techniques for deciphering encrypted messages without the use of a key. This field involves the analysis and breaking of cryptographic systems with the aim of recovering plaintext from ciphertext without having access to the cryptographic key used in the encryption process. Cryptanalysis helps identify weaknesses in encryption algorithms and can reveal the effectiveness of a given encryption method by testing its resistance against various attack techniques.

While the other options are related to the broader field of cryptography, they do not capture the essence of cryptanalysis. Studying encryption methods is more about understanding how they work rather than attempting to break them. The development of new encryption algorithms is a separate area of focus aimed at improving security rather than analyzing existing security measures. Creating strong passwords for encryption addresses key management and security practices but is not directly related to the art and science of breaking encryption techniques, which is where cryptanalysis is centered.