Crypt key has the same format as the corresponding property in IDKit PRO SDK, i.e. it consists of 32 bytes. The 32 bytes may be characters of a password or they may be generated in more sophisticated fashion. Create textual or binary file containing 32 characters/bytes (beware of UTF-16 encoding which might create 64-byte file from 32 characters) and put name of the file in <keyfile> element in IMatcher.xml or IDispatcher.xml.