Cyptography

Types of Cryptography

1. Symmetric Cryptography:
   • Uses a single key for both encryption and decryption.
   • Fast and efficient.
   • Example: AES (Advanced Encryption Standard).
   • Use Case: Securing data at rest (e.g., files, databases).
2. Asymmetric Cryptography:
   • Uses a pair of keys:
     • Public Key (shared with others).
     • Private Key (kept secret).
   • Slower but allows secure communication without sharing the private key.
   • Example: RSA, ECC.
   • Use Case: Secure communication, digital signatures.
3. Hashing:
   • Converts data into a fixed-length hash value.
   • One-way (irreversible).
   • Example: SHA-256, SHA-3.
   • Use Case: Verifying data integrity (e.g., file checksums, password storage).

Symmetric Key Algorithms:

• AES (Advanced Encryption Standard): Modern and secure.
• DES (Data Encryption Standard): Obsolete due to vulnerabilities.

Asymmetric Key Algorithms:

• RSA: Widely used for secure data exchange.
• ECC (Elliptic Curve Cryptography): More efficient than RSA for the same level of security.

Hashing Algorithms:

• SHA-2: Secure, commonly used.
• SHA-3: A newer standard.
• Bcrypt/Argon2: Used for secure password hashing.

Cryptographic hash function

A cryptographic hash function is a mathematical algorithm that transforms an input (or “message”) into a fixed-size string of bytes, typically represented as a hexadecimal value. These functions are designed to ensure data integrity and security by providing specific cryptographic properties.

Common Cryptographic Hash Functions:

1. MD5: An older algorithm, now considered insecure due to vulnerabilities.
2. SHA-1: Superseded by more secure algorithms due to collision vulnerabilities.
3. SHA-2: Includes SHA-224, SHA-256, SHA-384, and SHA-512, commonly used and considered secure.
4. SHA-3: A newer standard with a different design (based on Keccak).
5. BLAKE2: Fast and secure, used in modern applications.
6. Argon2: Specifically designed for password hashing with memory-hard properties.

Non-cryptographic hash

A non-cryptographic hash is a type of hash function designed for efficiency and speed rather than security. Unlike cryptographic hash functions, which are used in security-sensitive applications like password hashing or digital signatures, non-cryptographic hash functions prioritize performance, making them suitable for tasks that do not require resistance to attacks.

Common Non-Cryptographic Hash Functions:

• xxHash: Extremely fast and efficient, often used in high-performance systems.
• MurmurHash: Designed for hash-based lookup systems.
• FNV (Fowler–Noll–Vo): Simple and widely used for hash tables.
• CityHash: Optimized for use in systems where speed is critical.
• CRC32 (Cyclic Redundancy Check): Often used for error-checking in data transmission.