A known-plaintext attack (KPA) occurs when a hacker uses pairs of both encrypted and unencrypted data to uncover the encryption algorithm or key. The attacker has access to both the ciphertext (encrypted data) and the plaintext (original data), allowing them to analyze the relationship between the two. Techniques such as frequency analysis and pattern matching are commonly used in these attacks. The attacker gathers known pairs, analyzes patterns, guesses the cipher, and ultimately breaks the encryption based on discovered rules. Unlike chosen-plaintext attacks (CPA), where adversaries select plaintext to analyze, KPAs utilize already available data. To protect against KPAs, it is crucial to adopt strong encryption algorithms like AES, manage encryption keys securely, use unique keys for different sessions, and introduce randomness through cryptographic salts, ensuring that even repeated encryptions yield unique ciphertexts. Additionally, staying updated with the latest security fixes is essential to safeguard against such vulnerabilities.

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