Key Agreement Protocol

Key exchange protocols enable two or more parties to establish a shared encryption key that they can use to encrypt or sign data that they plan to exchange. Key exchange protocols typically employ cryptography to achieve this goal. Different cryptographic techniques can be used to achieve this goal.

In order for two parties to communicate confidentially, they must first exchange the secret key that will be used to encrypt and decrypt messages. This initial exchange the encryption key is called the key exchange.

Key exchange protocols are designed to solve the problem of confidentially when establishing a secret key between two or more parties without letting an unauthorized party somehow intercept, infer or otherwise obtain the key.

A naive example for a key exchange protocol is for one party to write down a secret key, place it in a tamper evident envelope and send it to the receiver. If the envelop is intact, then the secret key can be used by both parties to encrypt and decrypt messages.

Commonly used key-agreement protocols include Diffie-Hellman, or protocols that are based on RSA or ECC.

Frequently Asked Questions
What is Exponential key exchange?

Exponential key exchange often used to describe the Diffie-Hellman key exchange, is a method of securely exchanging a secret key between two parties by exploiting the mathematical characteristics of modular exponentiation, to enable two parties to securely learn a secret key over a public communications channel.

What is Diffie Hellman key exchange algorithm?

Diffie Hellman (DH) key exchange algorithm is a method of securely exchanging cryptographic keys over a public communications channel. It is named after their inventors Whitfield Diffie and Martin Hellman.

What is a key exchange algorithm?

Key exchange algorithm, often referred to as key exchange protocol, is any method in cryptography by which secret cryptographic keys are exchanged between two parties, usually over a public communications channel.