Patent ID: 7802310

Claim:
A computer-implemented method in a system which includes a network of computers, the method implemented at least in part by hardware comprising at least one processor, the method comprising the steps: (a) at a first computer, obtaining a content-based name for a particular data item from a second computer distinct from the first computer, the content-based name being based at least in part on a function of at least some of the data which comprise the contents of the particular data item, wherein the function comprises a message digest function or a hash function, and wherein two identical data items will have the same content-based name; and (b) by hardware in combination with software, a processor at said first computer ascertaining whether or not the content-based name for the particular data item corresponds to an entry in a database comprising a plurality of identifiers; and (c) based at least in part on said ascertaining in (b), determining whether or not access to the particular data item is authorized.