Patent ID: 8489612

Claim:
A method of identifying similar files in an environment having multiple client computers, comprising: receiving, at a first client computer from a coordinator computer, a request to find files located at the first client computer that are similar to at least one comparison file, wherein the request contains a signature of the at least one comparison file, and wherein the request has also been sent to other client computers by the coordinator computer to request that the other client computers also find files that are similar to the at least one comparison file; in response to the request, the first client computer comparing signatures of the files located at the first client computer with the signature of the at least one comparison file to identify at least a subset of the files located at the first client computer that are similar to the at least one comparison file according to a comparison metric, wherein each of the signatures of the files located at the first client computer includes a corresponding set of hash values representing chunks of the corresponding file, and wherein similarity of a given one of the files in the subset with the comparison file is represented by information including identifiers of the given file and the comparison file, and a count of a number of hash values shared by the given file and the comparison file; and sending, from the first client computer to the coordinator computer, a response produced based on the comparing, the response including an ordered list of hash values, where each corresponding hash value in the ordered list is associated with a respective list of files containing the corresponding hash value, and the response further includes a similarity data structure having plural entries each including a corresponding pair of identifiers of files and a count of a number of hash values shared by the files identified by the corresponding pair.