The most accurate definition of cryptography is centered on the concept of altering a message to ensure that it can only be easily read by the intended recipient. This encapsulates the essence of cryptography, which includes encoding or encrypting information to protect it from unintended access while still allowing authorized parties to decode or decrypt it for legitimate use.
Cryptography is fundamentally about securing communication and data to maintain confidentiality, integrity, and authenticity. By transforming information into a secure format that is unintelligible to anyone other than the intended recipient, cryptography plays a critical role in protecting sensitive information across various platforms and applications.
While ensuring data integrity, concealing physical formats, and securely storing passwords are all important aspects of information security, they do not encompass the broader concept of cryptography as effectively as the idea of restricting access solely to the intended recipient. Therefore, the notion of changing a message for exclusive readability reflects the core principle behind the use of cryptography in securing communication.