Cryptography Cheat Sheet

CIA Triad

• Confidentiality: Ensuring data is only accessible to authorized parties.
• Integrity: Ensuring data has not been altered or tampered with.
• Availability: Ensuring systems and data are accessible to authorized users when needed.

Symmetric Cryptography

• Uses a single, shared key for both encryption and decryption.
• Fast and efficient for large amounts of data.
• Challenge: Secure key distribution.
• Examples: AES, DES, 3DES, ChaCha20.

Asymmetric Cryptography (Public Key Cryptography)

• Uses a key pair: a Public Key (for encryption/verification) and a Private Key (for decryption/signing).
• Solves the key distribution problem.
• Slower and more computationally expensive than symmetric cryptography.
• Examples: RSA, ECC (Elliptic Curve Cryptography), Diffie-Hellman.

Hashing

• A one-way mathematical function that converts data into a fixed-size string of characters (hash/digest).
• Used for verifying data integrity and securely storing passwords.
• Properties: Deterministic, fast, pre-image resistance, collision resistance.
• Examples: SHA-256, SHA-3, MD5 (deprecated).