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Elliptic-curve Diffie–Hellman
Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol that allows two parties, each having an elliptic-curve public–private key pair, to establish a shared secret over an insecure channel. This shared secret may be directly used as a key, or to derive another key. The key, or the derived key, can then be used to encrypt subsequent communications using a symmetric-key cipher. It is a variant of the Diffie–Hellman protocol using elliptic-curve cryptography. Key establishment protocol The following example illustrates how a shared key is established. Suppose Alice wants to establish a shared key with Bob, but the only channel available for them may be eavesdropped by a third party. Initially, the domain parameters (that is, (p, a, b, G, n, h) in the prime case or (m, f(x), a, b, G, n, h) in the binary case) must be agreed upon. Also, each party must have a key pair suitable for elliptic curve cryptography, consisting of a private key d (a randomly selected intege ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Agreement
In cryptography, a key-agreement protocol is a protocol whereby two or more parties can agree on a key in such a way that both influence the outcome. If properly done, this precludes undesired third parties from forcing a key choice on the agreeing parties. Protocols that are useful in practice also do not reveal to any eavesdropping party what key has been agreed upon. Many key exchange systems have one party generate the key, and simply send that key to the other party—the other party has no influence on the key. Using a key-agreement protocol avoids some of the key distribution problems associated with such systems. Protocols where both parties influence the final derived key are the only way to implement perfect forward secrecy. Exponential key exchange The first publicly knownSee Diffie–Hellman key exchange for a more complete history of both the secret and public development of public-key cryptography. public-key agreement protocol that meets the above criteria was the Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |