gen-state-diffie-hellman-key-exchange-precisely-and-explain-why-dee5

State Diffie-Hellman key exchange precisely and explain why it matters in 2-3 sentences.

# Diffie-Hellman Key Exchange **Protocol:** Two parties agree on public parameters (prime *p* and generator *g*). Each party generates a private key (*a* or *b*), computes a public value (*g^a mod p* or *g^b mod p*), and exchanges these public values. Each party then raises the received public value to their own private key, yielding the same shared secret: *g^ab mod p*. **Why it matters:** Diffie-Hellman solved the fundamental problem of secure communication over insecure channels by allowing two parties who have never met to establish a shared secret key without ever transmitting it. This breakthrough (1976) enabled modern secure internet communication (HTTPS, VPNs, messaging) and proved that public-key cryptography was possible.