System and method for data access

A system for data access in a packet-switched network, comprising:

• a gateway including an operating unit, a memory and a processor connected to said packet-switched network in such a way that network packets sent between at least two other computers pass through it;
• a caching computer connected to said gateway through a fast local network, wherein said caching computer includes an operating unit, a first memory, a permanent storage memory and a processor;
• said caching computer further including a network cache memory in its permanent storage memory, means for a digital digest and means for comparison between a digital digest on data in its network cache memory and a digital digest received from said packet-switched network through said gateway.

A system for data access in a packet-switched network, comprising:

• a sender/computer including an operating unit, a first memory, a permanent storage memory and a processor and a remote receiver/computer including an operating unit, a first memory, a permanent storage memory and a processor, said sender/computer and said receiver/computer communicating through a network;
• said sender/computer further including means for creating digital digests on data, and
• said receiver/computer further including a network cache memory, means for storing a digital digest received from said network in its permanent storage memory and means for comparison between digital digests.

A method performed by a sender/computer in a packet-switched network for increasing data access, said sender/computer including an operating unit, a first memory, a permanent storage memory and a processor and said sender/computer being operative to transmit data to a receiver/computer, the method comprising the steps of:

• creating and transmitting a digital digest of said data from said sender/computer to said receiver/computer;
• receiving a response signal from said receiver/computer at said sender/computer, said response signal containing a positive, partial or negative indication signal for said digital digest, and
• if a negative indication signal is received, transmitting said data from said sender/computer to said receiver/computer.

A method for increasing data access performed by a sender/computer in a packet-switched network, said sender/computer including an operating unit, a first memory, a permanent storage memory and a processor and said sender/computer being operative to transmit principal data to a receiver/computer, said method comprising the steps of:

• creating and transmitting digital digests of said principal data and of one or more auxiliary data from said sender/computer to said receiver/computer;
• receiving a response signal at said sender/computer from said receiver/computer, said response signal containing a positive, negative or partial indication signal, and
• if a partial indication signal is received, said sender/computer transmitting a signal constituting the difference between said principal data and corresponding auxiliary data.

A method for increased data access performed by a computer system in a packet-switched network, said computer system including a network cache memory and being operationally interposed between a sender/computer and receiver/computer so that data packets sent between said sender/computer and said receiver/computer are delivered through said computer system;

• said method comprising the steps of:
• intercepting a message containing a digital digest transmitted from said sender/computer to said receiver/computer, and
• transmitting data with a digital digest substantially identical to the digital digest received from said sender/computer to said receiver/computer in response to said message, whereby said sender/computer is relieved of the burden of transmitting said data.

A method for increased data access performed by a client computer in a packet-switched network, said client computer including an operating unit, a first memory and a processor, said method comprising the steps of:

• sending a request for a single first data object from said client computer to a server, said request containing multiple digital digests for different data objects similar to said first data object;
• said server preparing a response to said request, searching for a second data object with a digital digest substantially identical to one of the digital digests received in said request, and producing the difference between said first data object and the uncovered second data object.