Introduction to Cryptography Notes Cryptography is the practice and study of techniques for secure communication in the presence of adversaries. It uses mathematical algorithms to convert a readable message, known as plaintext , into an unintelligible, coded message, known as ciphertext , and back again. The primary goals of cryptography are to ensure data security through: Confidentiality: Ensures that information can only be accessed by authorized parties. Integrity: Guarantees that data remains accurate and unaltered during transit or storage. Authentication: Verifies the identities of the sender and receiver. Non-repudiation: Prevents a sender from denying that they sent a message. Basic terminology and processes Encryption: The process of converting plaintext into ciphertext using an algorithm and a key. Decryption: The process of converting ciphertext back into plaintext using a key. Key: A piece of critic...