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I'm a beginner to ECC crypto programming. Can anyone explain to me the difference between using ECDH for shared key exchange and the use of ECIES by encrypting a shared key with the public key of the receiver?
I feel that ECIES could also provide me with secure key exchange as long as the private key is kept secret.
That's a bit of a strange question. ECDH is a key agreement protool. ECC does not have a direct form of encryption as RSA has. ECIES is basically ECDH used to derive a symmetric key, which is then used to encrypt the plaintext. You can see it as a delayed form of key agreement.
So your question is if ECIES can be used to encrypt session keys. That would come down to performing ECDH to derive a data key, and then using that data key to encrypt a session key. Yes, it is probably secure, but directly deriving a session key using ECDH is a lot easier. Using ECIES is only useful if - for some reason or other - authenticated DH key establishment cannot be integrated into a protocol.
For more information about using ECIES & ECDH for authentication, please see this other question.
