What is encryption used for in information security?

Encryption is a fundamental technique used in information security to protect sensitive data. It works by transforming readable data (plaintext) into an encoded format (ciphertext) using a specific algorithm and a key. This means that anyone who intercepts or accesses the encoded data will not be able to make sense of it without the corresponding decryption key, which is required to convert the encrypted data back into its original, readable form.

The primary purpose of encryption is to ensure confidentiality and protect data from unauthorized access, thus safeguarding sensitive information such as personal details, financial data, or proprietary business information. This capability makes encryption a cornerstone of secure communications and data protection practices across various industries and applications.

The other options describe different processes that are not related to encryption. For instance, permanently deleting files pertains to data elimination, altering data format relates to accessibility improvements rather than securing data, and compressing data is focused on reducing file sizes, which does not inherently provide any security measures.