Which of these would be considered the most important part of cryptography?

The most important part of cryptography is protecting the keys. In cryptographic systems, keys are essential for both encryption and decryption processes. If an attacker gains access to the cryptographic keys, they can easily bypass security measures and decrypt sensitive data, rendering the encryption ineffective.

Key management involves generating, storing, distributing, and revoking keys. However, the act of protecting them is paramount because no matter how secure the algorithms or encryption methods are, compromised keys can lead to a total failure of the cryptographic system's intended security. Thus, ensuring that keys are properly safeguarded from unauthorized access or theft is critical in maintaining the integrity and confidentiality of encrypted information.

Protecting the algorithms, managing the keys, and encrypting the data are important aspects of a comprehensive cryptographic strategy, but they do not hold the same level of significance as ensuring that the keys themselves are secured. This emphasis on key protection underscores the necessity of implementing strong key management practices.