Overview
Cryptography is the science of securing communication by converting information into a format that unauthorized individuals cannot understand. It ensures confidentiality, integrity, authentication, and non-repudiation.
Key Concepts
- Symmetric Encryption: Same key for encryption and decryption (e.g., AES, DES).
- Asymmetric Encryption: Public and private keys (e.g., RSA, ECC).
- Hash Functions: One-way algorithms producing fixed-length output (e.g., SHA-256).
- Digital Signatures: Ensure authenticity and integrity of messages.
Real-World Example
HTTPS websites use SSL/TLS, which relies on cryptographic algorithms, to secure communication between browsers and servers.
How to Implement Safely
- Always use strong and modern algorithms (avoid MD5, SHA-1).
- Use secure key management practices.
- Enable end-to-end encryption for sensitive communication.
- Combine hashing with salts to protect passwords.