The value to be used as the Authentication Key whenever the corresponding instance of zhRip2IfConfAuthType has a value other than noAuthentication. A modification of the corresponding instance of zhRip2IfConfAuthType does not modify the zhRip2IfConfAuthKey value. If a string shorter than 16 octets is supplied, it will be left- justified and padded to 16 octets, on the right, with nulls (0x00). Reading this object always results in an OCTET STRING of length zero; authentication may not be bypassed by reading the MIB object.