International Business Machines Corporation

Chee-Seng Chow

Marc Adam Kaplan

Joshua S Auerbach

Shay Kutten

Theodore E Tedijanto

Marcia Lambert Peters

Israel Cidon

Roch A Guerin

Michael James Ward

John E Drake, Jr

Inder Sarat Gopal

Levent Gun

Hamid Ahmadi

John G Dudley

Jeane S Chen

Allan K Edwards

Elizabeth A Hervatic

Prabandham M Gopal

Chandra Paul Immanuel

Jeffrey Charles Crigler

Rachel A Bodner

Marcell Mordechay Yung

Anthony M Lee

Joshua Seth Auerbach

Elizabeth Anne Hervatic

John Ellis Drake

Prabandham Madan Gopal

A system for identifying the authorized receiver of any particular copy of a document. More specifically, each particular copy of a document is fingerprinted by applying a set of variations to a document, where each variation is a change in data contents, but does not change the meaning or perusal experience of the document. A database associating a set of variants to a receiver is maintained. Thus any variant or copy of that variant can be traced to an authorized receiver.

Method to deter document and intellectual property piracy through

A method and apparatus to create, distribute, sell and control access to digital documents using secure cryptographic envelopes. An envelope is an aggregation of information parts, where each of the parts to be protected are encrypted with a corresponding part encryption key. These encrypted information parts along with the other information parts become part of the envelope. Each part encryption key is also encrypted with a public key, and these encrypted part encryption keys are also included in the envelope. The envelope also includes a list of parts where each entry in the list has a part name and a secure hash of the named part. The list is then signed with a secret key to generate a signature, which is also included in the envelope. The signature can be verified using a second public key associated with first secret key, and the integrity of any information part in the envelope can be checked by computing a second hash and comparing it with the corresponding hash in the list of parts. Also, the information content of any encrypted part can only be recovered by knowledge of a second secret key corresponding to the public key that was used to encrypt the part encryption keys.

Creation and distribution of cryptographic envelope

A packet communications network in which multicast transmissions are made reliable by transmitting acknowledgements to all neighbors of every receiving node, including the source node. This allows the relinquishment of message holding buffers as soon as all near neighbors acknowledge receipt of the message after only tile longest round trip time to the nearest neighbors, rather than the round trip to the furthest destination. Moreover, highly reliable ancillary point-to-point transmission facilities can be used to retransmit multicast messages indicated as being lost by failure of acknowledgment. Finally, network partitions occurring during the multicast procedure do not necessarily lose the multicast message to the remote partitions since any node receiving the message can insure delivery to all other nodes in that partition.

Reliable multicasting over spanning trees in packet communications

In a multicast network communication system, administration of the communication path making up the multicast tree itself has been separated from control and administration of the network. Creation of a multicast distribution tree and control over the membership thereof, is separately controlled independently from the creation and use of the tree transmission path used to communicate among the members of a multicast set. Transmission distribution trees are set up when a transmission request is received and the properties of the transmission path that is required are known. Transmission paths are created and controlled by all nodes in the communications system, each node having necessary control code and processors for responding to requests from set members to transmit a message to groups of users by creating and activating the necessary tree communication path distribution linkages. A distribution tree is created by the Tree Leader by generating a tree address using a random number generator. A tree address correlator is generated utilizing network and node identifiers unique for the network, and a list of subnodes or users connected for each member of the multicast tree set is generated. Using this information, a tree distribution path is computed to cover all of the subnodes required and a tree set up request message is sent by the Tree Leader along a computed path to each involved subnode. Each subnode returns a message indicating whether the tree address is already in use or is available for use. Successfully negotiated tree addresses are marked at the path link initiation and termination points at each node through the network.

Multicast communication tree creation and control method and apparatus

A packet communications system utilizes a route determining mechanism by identifying principal paths between the source and the destination in the system. Principal paths are minimum hop count paths with a transmission delay less than a specified threshold. Principal path links are accepted as legs of the optimum path, if feasible, i.e., if the resulting load on the link is less than a specified principal threshold. Secondary links are accepted only if the resulting load on the link is less than a specified secondary threshold, where the secondary threshold is less than the principal threshold. All paths must also have a transmission delay less than a specified threshold. Each request for a route includes the source node, the destination node, the load required, the maximum transmission delay and, if desired, the quality of service parameters which all of the legs of the route must satisfy. A modified Bellman-Ford breadth-first search algorithm is used to identify the principal links and, using these principal link identifications, determining the optimum path.

Methods and apparatus for optimum path selection in packet transmission

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Ossining, NY, United States of America

Chee-Seng Chow