What is the process called when data is translated into code that only someone with the correct key can access?

The process of translating data into a coded form so that only someone with the correct key can access it is known as encryption. This technique is used to secure sensitive information by converting it into a format that is unreadable to unauthorized users. The encryption algorithm takes the original data, referred to as plaintext, and transforms it into ciphertext using a key. Without this key, the encrypted data cannot be easily returned to its original form, making it a fundamental aspect of data security.

In contrast, decryption refers to the process of converting ciphertext back into plaintext using the correct key. Encoding, on the other hand, is a technique that may change the format of data for various purposes, such as transmission or storage, but does not inherently protect it from unauthorized access. Data compression reduces the size of data files for storage efficiency, but it does not involve any security measures regarding access.