Introduction Summary

Cryptography · Axiom Academy

SUMMARY Introduction to Cryptography Let's review the foundational concepts of cryptography and information security. Definition: The science and practice of securing communication and data in the presence of adversaries Goal: Protect information by transforming it into a form that only authorized parties can understand Modern Focus: Uses mathematical algorithms and computational complexity to ensure security Applications: Secure messaging, online banking, e-commerce, digital signatures, and authentication Plaintext: The original, readable message before encryption Ciphertext: The encrypted, unreadable message after encryption Encryption: The process of converting plaintext to ciphertext using an algorithm and key Decryption: The reverse process of converting ciphertext back to plaintext Key: Secret information used by the encryption/decryption algorithm Key Structure: Uses the same key for both encryption and decryption Speed: Fast and efficient for large amounts of data Key Distribution: Requires secure channel to share the secret key Examples: AES, DES, 3DES, ChaCha20 Use Cases: File encryption, disk encryption, secure communications after key exchange Key Structure: Uses a pair of keys - public key for encryption, private key for decryption Speed: Slower than symmetric encryption due to complex mathematical operations Key Distribution: Public key can be freely shared; private key must remain secret Examples: RSA, ECC (Elliptic Curve Cryptography), ElGamal

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