Understanding EC Diffie-Hellman. | by Pierre Philip du Pree…

Understanding EC Diffie-Hellman. | by Pierre Philip du Preez

• ECDH and ECDHE cipher suites are widely used in web server security for secure key exchange.
• The original Diffie-Hellman (DH) protocol, created in 1976, allows two parties to securely share a secret over an unsecured channel.
• Traditional symmetric encryption requires a secure channel for key exchange, which can be vulnerable to interception.
• In cryptography, a key is a string used for data encryption and decryption, with ECDH providing similar security to DH but with smaller key sizes.
• The DH protocol enables shared secret generation without a secure channel, facilitating encrypted communication afterward.
• The DH process involves generating a prime number and base number, exchanging computed values, and using modular arithmetic to derive a shared secret.
• ECDH functions like DH but uses elliptic curves for key generation, allowing for faster computations and smaller key sizes due to the elliptic curve discrete logarithm problem's complexity.
• An elliptic curve is a mathematical structure defined by a specific equation, which supports secure key exchanges in ECDH.
• In ECDH, both parties agree on an elliptic curve and its parameters, generate private keys, compute public keys, and exchange them to derive a shared secret for encryption.
• The use of elliptic curves in ECDH improves performance, particularly in high-traffic applications, by reducing computational overhead compared to traditional DH methods.