Symmetric Encryption

• Uses a single key for both encryption and decryption
• Often referred to as private key encryption
• Requires both sender and receiver to share the same secret key
• Offers confidentiality but lacks non-repudiation
• Challenges with key distribution in large-scale usage:
  • More people means more sharing of the keys

Asymmetric Encryption

• Uses two separate keys
  • Public key for encryption
  • Private key for decryption
• Often called “Public Key Cryptography”
• No need for shared secret keys
• Commonly used algorithms include Diffie-Hellman, RSA, and Elliptic Curve Cryptography (ECC)
• Slower compared to symmetric encryption but solves key distribution challenges

Hybrid Approach

• Combines both symmetric and asymmetric encryption for optimal benefits
• Asymmetric encryption used to encrypt and share a secret key
• Symmetric encryption used for bulk data transfer, leveraging the shared secret key
• Offers security and efficiency

Stream Cipher

• Encrypts data bit-by-bit or byte-by-byte in a continuous stream
• Uses a keystream generator and exclusive XOR function for encryption