What is the primary function of an encryption algorithm?

The primary function of an encryption algorithm is to transform plaintext into ciphertext. This process is essential in the realm of information security because it ensures that sensitive information is protected from unauthorized access. When plaintext, which is readable data, is processed through an encryption algorithm, it is converted into ciphertext, which appears as random, nonsensical characters to anyone who attempts to access the information without the proper decryption key. This transformation safeguards the confidentiality of the data, making it critical for protecting personal and organizational information during storage and transmission.

In contrast, the other options do not align with the core purpose of encryption. For instance, ensuring data is permanently deleted pertains to data destruction rather than its security in terms of confidentiality. Monitoring data access relates to oversight and auditing of how data is used, which is separate from the act of encrypting the data itself. Validating user identities involves authentication processes that confirm a user's legitimacy, but it does not encompass the encryption of data. Therefore, the definition of encryption is specifically tied to the conversion of plaintext to ciphertext, highlighting its fundamental role in security protocols.