-- | -- Module : Crypto.PubKey.ECIES -- License : BSD-style -- Maintainer : Vincent Hanquez <vincent@snarc.org> -- Stability : experimental -- Portability : unknown -- -- IES with Elliptic curve <https://en.wikipedia.org/wiki/Integrated_Encryption_Scheme> -- -- This is a simple cryptographic system between 2 parties using Elliptic Curve. -- -- The sending party create a shared secret using the receiver public key, and use the shared secret -- to generate cryptographic material for an symmetric encryption scheme (preferably authenticated encryption). -- -- The receiving party receive the temporary ephemeral public key which is combined to its secret key -- to create the shared secret which just like on the sending is used to generate cryptographic material. -- -- This module doesn't provide any symmetric data encryption capability or any mean to derive -- cryptographic key material for a symmetric key from the shared secret. -- this is left to the user for now. -- module Crypto.PubKey.ECIES ( deriveEncrypt , deriveDecrypt ) where import Crypto.ECC import Crypto.Error import Crypto.Random -- | Generate random a new Shared secret and the associated point -- to do a ECIES style encryption deriveEncrypt :: (MonadRandom randomly, EllipticCurveDH curve) => proxy curve -- ^ representation of the curve -> Point curve -- ^ the public key of the receiver -> randomly (CryptoFailable (Point curve, SharedSecret)) deriveEncrypt proxy pub = do (KeyPair rPoint rScalar) <- curveGenerateKeyPair proxy return $ (\s -> (rPoint, s)) `fmap` ecdh proxy rScalar pub -- | Derive the shared secret with the receiver key -- and the R point of the scheme. deriveDecrypt :: EllipticCurveDH curve => proxy curve -- ^ representation of the curve -> Point curve -- ^ The received R (supposedly, randomly generated on the encrypt side) -> Scalar curve -- ^ The secret key of the receiver -> CryptoFailable SharedSecret deriveDecrypt proxy point secret = ecdh proxy secret point