Method and system for packet scrambling communication with reduced processing overhead

• US 5,757,922 A
• Filed: 12/06/1996
• Issued: 05/26/1998
• Est. Priority Date: 12/08/1995
• Status: Expired due to Term

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Shiroshita, Teruji
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/761,434
• Time in Patent Office: 536 Days
• Field of Search: 38/9, 38/28, 38/29, 38/37, 38/43, 38/49, 38/50, 38/59, 38/4, 38/23, 38/25, 38/48
• US Class Current: 380/42
• CPC Class Codes: H04L 12/22 Arrangements for preventing the taking of data from a data transmission channel without authorisation means for verifying the identity or the authority of a user of a secure or secret communication system H04L9/32
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload

Abstract

A packet scrambling communication scheme capable of reducing the processing amount and the processing time required for the scrambling processing and the descrambling processing at the transmitting side and the receiving side. The original data is scrambled at the transmitting side, by dividing the original data into a plurality of data units in packet sizes, assembling packets by storing the data units into the packets and attaching false packet identifiers indicating a scrambled packet order to the packets, and transmitting the packets in the scrambled packet order according to the false packet identifiers from the transmitting side to the network. The packets received from the network are descrambled at the receiving side, by recovering a data unit order information indicating a descrambled order of the data units from the false packet identifiers, and reconstructing the original data from the data units stored in the packets according to the data unit order information.

Claims

1. A method for packet scrambling communication between a transmitting side and a receiving side connected through a network, comprising the steps of:

scrambling original data at the transmitting side, by dividing the original data into a plurality of data-units, assembling packets by storing the data-units in the packets and attaching to the packets scrambled packet identifiers indicating a scrambled packet order so that the packets can be scrambled by being rearranged according to the scrambled packet identifiers, and transmitting the packets in the scrambled packet order according to the scrambled packet identifiers from the transmitting side to the network;

descrambling the packets received from the network at the receiving side, by recovering data-unit order information indicating a descrambled order of the data-units from the scrambled packet identifiers, and reconstrucitng the original data from the data-units stored in the packets according to the data-unit order information.

2. The method of claim 1, wherein:

the scrambing step assembles the packets by attaching to the packets non-scrambled packet identifiers indicating a non-scrambled packet order, and replacing the non-scrambled packet identifiers by the scrambled packet identifiers according to a prescribed scrambing key; and

the descrambling step recovers data-unit order information by converting the scrambled packet identifiers into the non-scrambled packet identifiers according to a prescribed descrambling key corresponding to the prescribed scrambling key, and using the non-scrambled packet identifiers as the data-unit order information in reconstructing the original data.

3. The method of claim 1, wherein:

the scrambling step assembles the packets by directly calculating the scrambled packet identifiers from memory addresses of the data-units according to a prescribed calculation procedure; and

the descrambling step recovers the data-unit order information by directly calculating the memory addresses of the data-units from the scrambled packet identifiers according to the prescribed calculation procedure, and using the memory addresses as the data-unit order information in reconstructing the original data.

4. The method of claim 1, wherein the scrambling step is carried out by a protocol processing at the transmitting side.

5. The method of claim 1, wherein the descrambling step is carried out by a protocol processing at the receiving side.

6. The method of claim 1, wherein the scrambling step divides the original data and assembles the packets during idle times available in a process for transmitting the packets.

7. The method of claim 1, wherein the descrambling step recovers the data-unit order information and reconstructs the original data during idle times available in a process for receiving the packets.

8. The method of claim 1, wherein the scrambling step transmits a prescribed number of the packets together, and when the original data is not divisible by the prescribed number, the scrambling step assembles the packets by inserting at least one padding packet so as to form the prescribed number of the packets to be transmitted together.

9. The method of claim 1, further comprising the steps of:

sending a negative acknowledgment indicating the scrambled packet identifiers of unreceived packets from the receiving side to the transmitting side; and

re-transmitting the packets with the scrambled packet identifiers corresponding to the unreceived packets from the transmitting side to the receiving side according to the scrambled packet identifiers indicated in the negative acknowledgement.

10. The method of claim 1, further comprising the step of:

relaying the packets transmitted from the transmitting side at a relay device provided in the network, by changing a destination specified in each packet according to a destination conversion table provided in the relay device, the destination conversion table indicating a next transfer target or a final destination of each packet corresponding to the destination specified in each packet.

11. A system for packet scrambling communication, comprising:

a network;

a transmission device connected with the network, including;

scrambling processing means for scrambling original data, by dividing the original data into a plurality of data-units, and assembling packets by storing the data-units in the packets and attaching to the packets scrambled packet identifiers indicating a scrambled packet order so that the packets can be scrambled by being rearranged according to the scrambled packet identifiers; and

transmission means for transmitting the packets in the scrambled packet order according to the scrambled packet identifiers to the network; and

a receiving device connected with the network, including;

receiving means for receiving the packets from the network; and

descrambling processing means for descrambling the packets, by recovering data-unit order information indicating a descrambled order of the data-units from the scrambled packet identifiers, and reconstructing the original data from the data-units stored in the packets according to the data-unit order information.

12. The system of claim 11, wherein:

the scrambling processing means assembles the packets by attaching to the packets non-scrambled packet identifiers indicating a non-scrambled packet order and replacing the non-scrambled packet identifiers by the scrambled packet identifiers according to a prescribed scrambing key; and

the descrambling processing means recovers the data-unit order information by converting the scrambled packet identifiers into the non-scrambled packet identifiers according to a prescribed descrambling key corresponding to the prescribed scrambling key, and using the non-scrambled packet identifiers as the data-unit order information in reconstructing the original data.

13. The system of claim 11, wherein:

the scrambling processing means assembles the packets by directly calculating the scrambled packet identifiers from memory addresses of the data-units according to a prescribed calculation procedure; and

the descrambling processing means recovers the data-unit order information by directly calcualting the memory addresses of the data-units from the scrambled packet identifiers according to the prescribed calculation procedure, and using the memory addresses as the data-unit order information in reconstrucing the original data.

14. The system of claim 11, wherein the scrambling processing means divides the original data and assembles the packets by executing a protocol processing.

15. The system of claim 11, wherein the descrambling processing means recovers the order information and reconstructs the original data by executing a protocol processing.

16. The system of claim 11, wherein the scrambling processing means divides the original data and assembles the packets during idle times available in a process for transmitting the packets by the transmission means.

17. The system of claim 11, wherein the descrabling processing means recovers the data-unit order information and reconstructs the original data during idle times available in a process for receiving the packets by the receiving means.

18. The system of claim 11, wherein the transmission means transmits a prescribed number of the packets together, and when the original data is not divisible by the prescribed number, the scrambling processing means assembles the packets by inserting at least one padding packet so as to form the prescribed number of the packets to be transmitted together.

19. The system of claim 11, wherein:

the receiving device further includes means for sending a negative acknowledgement indicating the scrambled packet identifiers of unreceived packets to the transmission device; and

the transmission device further incudes means for retransmitting the packets with the scrambled packet identifiers corresponding to the unreceived packets to the receiving device according to the scrambled packet identifiers indicated in the negative acknowledgement.

20. The system of claim 11, further comprising:

a relay device, provided in the network, for relaying the packets transmitted from the transmission device, the relay device including;

a destination conversion table indicating a next transfer target or a final destination of each packet corresponding to a destination specified in each packet; and

transfer means for changing the destination specified in each packet according to the destination conversion table, and transferring each packet with a changed destination to the network.