System and method for selectively scrambling multidimensional digital frame structure communications
AssigneeApplied Micro Circuits Corporation
InventorsGeorge Beshara Bendak, Alan Michael Sorgi
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Abstract
A system and method have been provided to increase security in scrambled communications by periodically changing the seed masks used to generate the scrambling algorithms at the transmitter and receiver. The scrambling algorithm is changed by periodically modifying the seed masks which establishes the initial state of the scrambling algorithm generators. The same seed mask key is passed through an auxiliary communication channel to the receiver to insure that matching descrambling algorithms are generated.
Claims32
A method for scrambling communications formatted in a digital frame structure, comprising:
- forming superframes from a first plurality of frames;
- defining a scrambling structure;
- selectively seeding the scrambling structure;
- wherein selectively seeding the scrambling structure includes selectively initializing the scrambling structure with a seed mask;
- wherein selectively seeding the scrambling structure further includes selecting a seed mask every superframe;
- and
- wherein selectively seeding the scrambling structure further includes selecting a seed mask from a second plurality of seed masks;
- generating a selectable scrambling algorithm from the selectively seeded scrambling structure;
- and
- scrambling communications in a frame using the selectable scrambling algorithm;
- wherein scrambling communications using the selectable scrambling algorithm includes scrambling the communications with a second plurality of scrambling algorithms.
A method for programmably descrambling a multidimensional digital frame structure, the method comprising:
- receiving scrambled communications;
- wherein receiving scrambled communications includes receiving scrambled communication superframes, with each superframe including frame synchronization bytes;
- defining a descrambling structure;
- selectively seeding the descrambling structure;
- wherein selectively seeding the descrambling structure includes periodically changing the descrambling structure seed mask;
- wherein selectively seeding the descrambling structure further includes selecting a seed mask every superframe;
- generating a selectable descrambling algorithm responsive to the selective seeding of the descrambling structure;
- and
- descrambling the communications using the selectable descrambling algorithm;
- wherein descrambling communications using the selectable descrambling algorithm includes synchronously descrambling the communications in each superframe in response to the superframe frame synchronization bytes.
A system for programmably scrambling a multidimensional digital frame structure, the system comprising:
- a transmitter including:
- a scrambling algorithm generator having an input to accept a seed mask and an output to supply a scrambling algorithm responsive to the structure of the algorithm generator and the seed mask;
- a transmit seed mask generator having a first input to accept seed selection commands and an output connected to the scrambling algorithm generator input to selectively supply seed masks;
- a scrambler having a first input to accept communications and a second input connected to the scrambling algorithm generator output, the scrambler having an output to supply communications scrambled with the scrambling algorithm responsive to the selected seed mask.
A method for communicating among nodes in a network of communication nodes, the method comprising:
- sending a descrambling key to selected nodes in the network;
- receiving the descrambling key at the selected nodes;
- and
- selecting a seed mask in response to the descrambling key;
- generating a scrambling algorithm from the first seed mask;
- generating a descrambling algorithm from the first seed mask;
- scrambling a communication in the network using the scrambling algorithm;
- and
- descrambling the communication at the selected nodes using the descrambling algorithm.
Dependencies are inferred from the claim text.