Which of the following best defines cryptography?

Cryptography is fundamentally defined as a technique for transforming readable information into an unreadable format. This is achieved through algorithms and keys that encode the data, ensuring that only those who possess the correct key can decode and access the original information. This transformation is essential for maintaining confidentiality, integrity, and authenticity in communication and data storage.

In the context of digital security, cryptography plays a crucial role in protecting sensitive information from unauthorized access and ensuring secure data transmission over potentially insecure networks. By transforming data into an unreadable format, it safeguards against eavesdropping and data breaches.

The other options, while related to aspects of data security and management, do not accurately capture the essence of what cryptography entails. They focus instead on broader concepts such as access management, network maintenance, and threat monitoring, which are integral to cybersecurity but distinct from the specific function of cryptography itself.