function createECDH
#createECDH(curveName: string): ECDHCreates an Elliptic Curve Diffie-Hellman (ECDH) key exchange object using a
predefined curve specified by the curveName string. Use getCurves to obtain a list of available curve names. On recent
OpenSSL releases, openssl ecparam -list_curves will also display the name
and description of each available elliptic curve.
Parameters #
#curveName: string