Symmetric vs Asymmetric Cryptography

Cryptography · Axiom Academy

LESSON Symmetric vs Asymmetric Cryptography Understanding the fundamental distinction between shared secret and public-key cryptography In symmetric cryptography, both the sender and receiver use the same secret key for both encryption and decryption. This shared key must be kept confidential and securely exchanged before communication can begin. Single shared key: Both parties use the same secret key K Fast encryption: Symmetric algorithms are computationally efficient Key distribution problem: How do you securely share the key initially? Examples: AES, DES, 3DES, ChaCha20 2. Asymmetric Key Cryptography Asymmetric cryptography uses a pair of mathematically related keys : a public key (which can be freely shared) and a private key (which must be kept secret). Data encrypted with one key can only be decrypted with the other. Key pair: Public key for encryption, private key for decryption No key exchange needed: Public keys can be shared openly Slower than symmetric: More computationally intensive Examples: RSA, ECC (Elliptic Curve), Diffie-Hellman 3. Hybrid Approach and Key Exchange Modern cryptographic systems often use a hybrid approach : asymmetric cryptography solves the key distribution problem by securely exchanging a symmetric key, then symmetric cryptography handles the bulk of data encryption for efficiency.

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