Methods and systems for securing information communicated between communication devices

• US 7,430,292 B2
• Filed: 04/08/2002
• Issued: 09/30/2008
• Est. Priority Date: 04/07/2001
• Status: Expired due to Fees

• Current Assignee: TeleHubLink Corp.
• Original Assignee: Telenublink Corporation
• Inventors: Lekkas, Panos C., Nichols, Randall K., Giorgio, Edward J., LaPat, Ronald H.
• Primary Examiner(s): Barron, Jr.; Gilberto
• Assistant Examiner(s): LASHLEY, LAUREL L
• Application Number:
  US10/118,136
• Publication Number:
  US 20020176578A1
• Time in Patent Office: 2,367 Days
• Field of Search: 380/46, 380/42
• US Class Current: 380/42
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic

Abstract

A system is provided for generating information for secure transmission from a first device to a second device. The system comprising a key scheduler for generating a dynamic secret key, a synchronization generator for generating a synchronization sequence and controlling the frequency of the dynamic secret key, a padding generator for generating a padding sequence, and a DEK generator for generating encrypted text. The system generating a stream of encrypted information that includes the synchronization sequence prior to and adjacent the encrypted text which is prior to and adjacent the padding sequence.

Claims

1. A method for encrypting information for communication between a first device and a second device, said method comprising:

generating a random number in the first device;

subjecting the random number to a logical XOR component in the first device;

transmitting the XOR'"'"'ed random number to a linear-feedback-shift register (LFSR) accumulator in the first device;

providing bits from the LFSR accumulator to a register in the first device; and

transmitting an output from the register to a second linear-feedback-shift register in the first device.

2. A method in accordance with claim 1 further comprising utilizing taps to provide the bits from the LFSR accumulator to the register.

3. A method in accordance with claim 1 further comprising providing bits from the LFSR accumulator to the register through the XOR component.

4. A method in accordance with claim 1 further comprising:

receiving and storing the contents of the register in a multiplexer; and

selectively outputting the contents of the multiplexer.

5. A method in accordance with claim 1 wherein the register is located at a first device and the first device register has a first bit sequence having pre-determined number of values, the first bit sequence representing a secret key α

, said method further comprising the steps of;

shifting the first bit sequence at least one bit position to generate a first at least one additional value;

loading the first at least one additional value onto the first device register; and

generating a second bit sequence with the first device register utilizing the first at least one additional value.

6. A method in accordance with claim 5 further comprising the steps of:

shifting the second bit sequence at least one position to generate a second at least one additional value;

loading the second at least one additional value onto the first device register; and

generating a third bit sequence with the first device register utilizing the second at least one additional value.

7. A method in accordance with claim 5 further comprising subjecting the secret key α

to a conventional Diffie Hellman equation to generate a public key Y_α

, wherein the Diffie Hellman equation is characterized by the equation, Y_α

=g^α

mod p, where Y_α

is the public key;

g is a generator sequence of ones and zeros known to the first device and the second device, and p is a large prime number known to the first device and the second device.

8. A method in accordance with claim 7 further comprising communicating the public key Y_α

from the first device to the second device.

9. A method in accordance with claim 7 wherein the register is located at a second device and the second device register has a first bit sequence having pre-determined number of values, the second device register first bit sequence representing a secret key β

, further comprising subjecting the secret key β

to a conventional Diffie Hellman equation to generate a public key Y_β

, wherein the Diffie Hellman equation is characterized by the equation, Y_β

=g^β

mod p, where Y_β

is the public key;

g is the generator sequence, and p is the large prime number.

10. A method in accordance with claim 9 further comprising communicating the public key Y_β

from the second device to the first device.

11. A method in accordance with claim 9 further comprising processing, at the second device, the public key Y_α

to generate a shared secret key Y<sub>α

β</sub>

utilizing the equation Y<sub>α

β</sub>

=(Y_α

)^β

mod p.

12. A method in accordance with claim 11 further comprising processing, at the first device, the public key Y_β

to generate a shared secret key Y<sub>α

β</sub>

utilizing the equation Y<sub>α

β</sub>

=(Y_β

)^α

mod p.

13. A method in accordance with claim 12 further comprising:

subjecting the second bit sequence to a secure hashing algorithm to generate a DEK-0 at the first device; and

communicating the DEK-0 from the first device to the second device.

14. A method in accordance with claim 5 further comprising:

subjecting the second bit sequence to a secure hashing algorithm to generate a DEK-0 at the first device; and

communicating the DEK-0 from the first device to the second device.

15. A method in accordance with claim 13 further comprising XOR'"'"'ing the DEK-0 at the first device with the shared secret key Y_α

β

to encrypt the DEK-0.

16. A method in accordance with claim 15 further comprising XOR'"'"'ing the received DEK-0 at the second device to decrypt the encrypted DEK-0.

17. A method in accordance with claim 13 further comprising:

subjecting the shared secret key Y<sub>α

β</sub>

to the secure hashing algorithm to generate a shared secret key digest; and

XOR'"'"'ing the shared secret key digest with the DEK-0 to encrypt the DEK-0.

18. A method in accordance with claim 17 further comprising XOR'"'"'ing, at the second device, the DEK-0 with the shared secret key digest to decrypt the DEK-0.

19. A system for encrypting information for communication between a plurality of devices, said system comprising:

a first communication device and a second communication device;

said first communication device comprising;

a random number generator;

a logical XOR component coupled to said random number generator;

a linear-feedback-shift register (LFSR) accumulator coupled to said logical XOR component;

a register coupled to said LFSR accumulator;

a multiplexer coupled to said register; and

a second linear-feedback-shift register operatively coupled to said register, said multiplexer transmitting an output from the register to said second linear-feedback-shift register.

20. A system in accordance with claim 19 further comprising a summing unit, said LFSR comprising a plurality of taps adapted to provide bits from said LFSR to said summing unit.

21. A system in accordance with claim 20 wherein said register is located at said first device and includes a first bit sequence having a pre-determined number of values, the first bit sequence representing a first key α

, said system configured to;

shift the first bit sequence at least one bit position to generate a first additional value;

load the first additional value onto said first device register; and

generate a second bit sequence with said first device register utilizing the first additional value.

22. A system in accordance with claim 21 further configured to:

shift the second bit sequence at least one position to generate a second additional value;

load the second additional value onto said first device register; and

generate a third bit sequence with said first device register utilizing the second additional value.

23. A system in accordance with claim 21 further configured to subject the first key α

to a conventional Diffie Hellman equation to generate a second key Y_α

, wherein the Diffie Hellman equation is characterized by the equation, Y_α

=g^α

mod p, where Y_α

is the second key;

g is a generator sequence of ones and zeros known to said first device and said second device, and p is a large prime number known to said first device and said second device.

24. A system in accordance with claim 23 wherein said second device comprises a register having a first bit sequence having pre-determined number of values, the second device register first bit sequence representing a third key β

, said system further configured to subject the third key β

to a conventional Diffie Hellman equation to generate a fourth key Y_β

, wherein the Diffie Hellman equation is characterized by the equation, Y_β

=g^β

mod p, where Y_β

is the fourth key;

g is the generator sequence, and p is the large prime number.

25. A system in accordance with claim 24 further configured to:

process, at said second device, the second key Y_α

to generate a shared secret key Y<sub>α

β</sub>

utilizing the equation Y<sub>α

β</sub>

=(Y_α

)^β

mod p; and

process, at said first device, the fourth key Y_β

to generate a shared secret key Y<sub>α

β</sub>

utilizing the equation Y<sub>α

β</sub>

=(Y_β

)^α

mod p.