A distributed data processing arrangement is disclosed including: a first data processing apparatus including a central processing unit; a first memory storing a descriptive data structure, said descriptive data structure including information regarding a first organisation of elements within a secure container, said information including information on the organisation of said elements within said secure container; and information on the location of at least some of said elements within said secure container; and communications means by which said descriptive data structure may be communicated to a data processing apparatus different from said first data processing apparatus;
a second data processing apparatus located at a site different from the site of said first data processing apparatus, said second data processing apparatus including a central processing unit; a second memory including: a first secure container comprising at least: data elements organised at least in part in accordance with the information contained in said descriptive data structure; and at least one rule used to at least in part govern at least one aspect of access to or use of said data elements; at least one of said rules requiring that information regarding at least one use of at least one of said data elements be temporarily recorded; and at least one computer program designed to use at least a portion of said descriptive data structure in at least one operation on said first secure container or the contents of said first secure container; said use including at least using said information regarding the organisation of elements within said first secure container in a process of identifying and/or locating at least one of said elements; and communications means by which said second data processing apparatus may receive at least a portion of said descriptive data structure or a copy thereof.