ECDHPublicBcpgKey
public ECDHPublicBcpgKey(DerObjectIdentifier oid, ECPoint point, HashAlgorithmTag hashAlgorithm, SymmetricKeyAlgorithmTag symmetricKeyAlgorithm)
public ECDHPublicBcpgKey(DerObjectIdentifier oid, BigInteger point, HashAlgorithmTag hashAlgorithm, SymmetricKeyAlgorithmTag symmetricKeyAlgorithm)