An encryption scheme is a systematic method used to transform readable data (plaintext) into an unreadable format (ciphertext) using mathematical algorithms and keys. The primary purpose is to protect sensitive information from unauthorized access during storage or transmission. Encryption schemes can be symmetric, where the same key is used for both encryption and decryption, or asymmetric, where different keys are used. The security of an encryption scheme depends on the strength of its algorithms and the secrecy of its keys. Common examples include AES (Advanced Encryption Standard) and RSA (Rivest–Shamir–Adleman). Encryption schemes are fundamental in cybersecurity, ensuring data privacy and integrity across digital communications.