Abstract: An electronic system architecture comprises a plurality of client devices connected in a hierarchical structure in which the client devices form nodes in the structure interconnected by communications links. One client device at the top of the hierarchical structure provides a gateway to a server and each other client device is connected to a single client device through a single communications link in an upstream direction and each client device is connected to a number, which may be zero, of client devices through the same number of communications links in a downstream direction. The downstream client devices have lower bandwidth requirements than any client devices upstream of them and the sum of the bandwidths of the communications links from each client device in a downstream direction is less than the bandwidth of the communications links in the upstream direction.

Abstract: A browser program which, when executed by a suitable device, causes the device to carry out the method steps of:

Abstract: A secure communications method comprises the steps of: fragmenting a digital message into a series of fragments, at least some of the fragments being smaller or larger than the smallest base unit of data used by the communications network: carrying out a reversible operation on the fragment stream, sending the fragment stream through at least one digital communication network; and reversing the operation carried out on the fragment stream to reproduce the digital message. The use of some fragments smaller or larger than the smallest base unit of data used by the network ensures that some of the fragments are non-symbolic. That is, the fragments do not correspond to symbols, symbols being the smallest unit of data used by communications network. Thus, frequency analysis attacks are thwarted.