Protecting data confidentiality through encryption
Encryption is the process of converting plaintext data into ciphertext to protect its confidentiality. Operating systems use encryption to secure data at rest (on storage devices) and data in transit (over networks). Basic encryption concepts include: 1) Symmetric encryption - Uses the same key for encryption and decryption (e.g., AES, DES). 2) Asymmetric encryption - Uses public/private key pairs (e.g., RSA, ECC). 3) Hash functions - One-way functions that produce fixed-size outputs (e.g., SHA-256). Operating systems employ encryption in various areas: file system encryption (e.g., BitLocker, FileVault), secure communication (SSL/TLS), password storage, and digital signatures. Modern systems also use techniques like full disk encryption, file-level encryption, and encrypted swap spaces to protect sensitive data. Understanding encryption basics is essential for system administrators to configure secure systems and for developers to implement proper data protection in applications.