Definition - What does Diffie-Hellman Key Exchange mean?
The Diffie-Hellmann key exchange is a secure method for exchanging cryptographic keys.
This method allows two parties which have no prior knowledge of each other to establish a shared, secret key, even over an insecure channel.
The concept uses multiplicative group of integers modulo, which without knowledge of the private keys of any of the parties, would present a mathematically overwhelming task to a code breaker .
Techopedia explains Diffie-Hellman Key Exchange
The key exchange was invented by Whitfield Diffie and Martin Hellmann in 1976 as the first practical method for establishing a shared secret code over an open communications channel.
The general idea of the Diffie-Hellmann key exchange involves two parties exchanging numbers and doing simple calculations in order to get a common number which serves as the secret key.
Both parties may not know beforehand what the final secret number is, but after some calculations, both are left with a value that only they know about which they can use for various purposes like identification and as a secret key for other cryptographic methods.