As a consequence, these Chelsfield controls are being used by many blue chip corporate organisations,  both in the UK and aboard.  The library features a proprietary one way key hash and polymorphic transformation techniques making it a very strong stream cipher that's fast enough to be used on-the-fly in most applications.  The code is less than 70k bytes, is self contained and does not rely on the Windows API    

The requirement: 80 sets of rugged telephone systems equipment that will be deployed in aid agency camps around the world with no access to telephone land lines. Chelsfield specified compact mobile satellite terminals hooked up to rugged cordless telephones with a 300 meter range operating from a D.E.C.T. (Digitally Enhanced Cordless Telephony) card in a rack based telephone system..

However, although the five main building blocks were flooded with CAT-5 structured cabling no multicore cable had been laid linking these together. Fortunately a One Gigabyte fibre was available from the central building to the other blocks. The solution: The TDM  (Time Divisional Multiplex) Hybrid telephone system was IP-enabled and 10-Meg Ethernet switches were specified in each of the separate buildings with IP telephones located as required. This solution came out at under half the cost of laying a multicore cable. 

The heart of the system is a new and very fast polymorphic stream cypher that is currently being used as a modular component in dozens of third party applications.  What makes this unique, is that the key hash is partly derived from the clear text of the message by a special algorithm. The message can actually be zero bytes long and yet still generate a unique 1024 bit key.