What does the process of encryption use to transform plaintext into ciphertext?

The process of encryption is fundamentally centered around the use of a cryptographic algorithm combined with a key. A cryptographic algorithm is a mathematical function used to transform the plaintext—the readable data—into ciphertext, which is the encoded data that appears random and is not easily interpretable without the proper key. The key plays a critical role as it dictates how the transformation occurs, providing a unique pathway for encoding and decoding the data.

This transformation ensures that even if an unauthorized party intercepts the ciphertext, they will have a significant challenge in deriving the original plaintext without access to the specific key used in the encryption process. In essence, without both the cryptographic algorithm and the key, the security provided by encryption would be compromised, making them integral to the encryption process.

Other options do not directly relate to the core function of encryption. A compression algorithm, for example, is not designed for securing data but rather for reducing the size of files. A transmission line refers to the medium through which data is transmitted, and while it may be relevant in the context of data security, it does not play a role in the transformation of plaintext to ciphertext. A filtering method similarly does not pertain to the encryption process itself, as it generally involves managing or controlling data flow