Method and system for enhancing cryptographic capabilities of a wireless device using broadcasted random noise

• US 8,254,574 B2
• Filed: 10/12/2007
• Issued: 08/28/2012
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Briancon, Alain C., Dodis, Yevgeniy, Shah, Yogendra C., Ye, Chunxuan, DiFazio, Robert A., Cha, Inhyok, Reznik, Alexander
• Primary Examiner(s): Homayounmehr, Farid
• Assistant Examiner(s): LEWIS, LISA C
• Application Number:
  US11/871,683
• Publication Number:
  US 20080089518A1
• Time in Patent Office: 1,782 Days
• Field of Search: 380/268
• US Class Current: 380/268
• CPC Class Codes: H04L 2209/08 Randomization, e.g. dummy operations or using noise
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/0457 wherein the sending and receiving network entities apply dynamic encryption, e.g. stream encryption cryptographic mechanisms or cryptographic arrangements for stream encryption H04L9/065
• CPC Class Codes: H04L 9/065 Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems, RC4, SEAL or A5/3
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds
• CPC Class Codes: H04L 9/0875 based on channel impulse response [CIR]
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/041 Key generation or derivation

Abstract

A secret stream of bits begins by receiving a public random stream contained in a wireless communication signal at a transmit/receive unit. The public random stream is sampled and specific bits are extracted according to a shared common secret. These extracted bits are used to create a longer secret stream. The shared common secret may be generated using JRNSO techniques, or provided to the transmit/receive units prior to the communication session. Alternatively, one of the transmit/receive unit is assumed to be more powerful than any potential eavesdropper. In this situation, the powerful transmit/receive unit may broadcast and store a public random stream. The weaker transmit/receive unit selects select random bits of the broadcast for creating a key. The weaker transmit/receive unit sends the powerful transmit/receive unit the selected bit numbers, and powerful transmit/receive unit uses the random numbers to produce the key created by the weaker transmit/receive unit.

Claims

1. A method implemented in a first transmit/receive unit for generating a secret stream of data based on received random public noise, the method comprising:

negotiating a session period with a second transmit/receive unit;

capturing random data from a random public noise stream for the session period, wherein the capturing is performed for a period of time long enough to exceed a storage limit of an eavesdropper;

storing the random data at the first transmit/receive unit in a storage that is larger than a memory capacity of the eavesdropper;

upon completion of the session period, receiving random numbers generated by the second transmit/receive unit from the second transmit/receive unit;

extracting a secret key from the random data by sampling the random data using the random numbers, wherein the second transmit/receive unit extracts the same secret key by sampling the random data using the random numbers during the session period; and

transmitting encrypted data to the second transmit/receive unit using the secret key for encryption.

2. The method of claim 1 wherein the second transmit/receive unit is a cellular base station.

3. The method of claim 1 wherein the extracting is performed when the first transmit/receive unit is in sleep mode.

4. The method of claim 1 further comprising generating the random public noise stream at the first transmit/receive unit.

5. The method of claim 4 further comprising receiving a request to adjust the random public noise stream'"'"'s randomness rate.

6. The method of claim 5 further comprising determining that the request is received from an authorized device.

7. The method of claim 1 further comprising transmitting a request to adjust the random public noise stream'"'"'s randomness rate.

8. The method of claim 1 wherein transmitting the encrypted data includes transmitting the encrypted data to more than two transmit/receive units.

9. The method of claim 1 wherein the random public noise stream is transmitted by a base station in a cellular network.

10. The method of claim 1 wherein the random public noise stream is transmitted as part of a non-cellular wireless communication system.

11. A first wireless transmit/receive unit (WTRU) for transmitting and receiving encrypted data using public random noise;

the WTRU comprising;

a receiver that;

receives session period negotiation data from a second WTRU,

captures random data from a random public noise stream for a negotiated session period, wherein the capturing is performed for a period of time long enough to exceed the storage limit of an eavesdropper, and

upon completion of the negotiated session period, receives random numbers generated by the second WTRU from the second WTRU;

a memory that stores random data captured from the random public noise stream, wherein the memory is larger than a memory capacity of the eavesdropper;

a processor that executes instructions for;

determining the negotiated session period,

extracting a secret key from the random data by sampling the random data using the random numbers, wherein the second WTRU extracts the same secret key by sampling the random public noise stream using the random numbers during the negotiated session period, and

generating encrypted data using the secret key for encryption; and

a transmitter that transmits the encrypted data to the second WTRU.

12. The first WTRU of claim 11 wherein the receiver further receives second encrypted data, and the processor further executes instructions for decrypting the second encrypted data using the secret key.

13. The first WTRU of claim 11 wherein the transmitter further transmits a request to adjust the randomness rate of the random public noise.

14. The first WTRU of claim 11 wherein the receiver further receives a request to adjust the randomness rate of the random public noise.

15. The first WTRU of claim 14 wherein the processor further executes instructions for determining that the request is received from an authorized device.

16. The first WTRU of claim 11 wherein the random public noise stream is received from a base station.

17. The first WTRU of claim 11 wherein the random public noise stream is received from part of a non-cellular wireless communication system.

18. The first WTRU of claim 11 wherein the processor further executes instructions for generating the random public noise stream and the transmitter further transmits the random public noise stream.

19. A method of generating an encrypted stream of data comprising:

negotiating, at a first transmit/receive unit, a session period with a second transmit/receive unit;

transmitting a public stream of random noise for the session period from the first transmit/receive unit to the second transmit/receive unit, wherein the transmission is performed for a period of time long enough to exceed the storage limit of an eavesdropper;

storing the public stream of random noise on a storage device of the first transmit/receive unit, wherein the storage device of the first transmit/receive unit is larger than a memory capacity of the eavesdropper;

receiving random numbers at the first transmit/receive unit generated by the second transmit/receive unit from the second transmit/receive unit upon completion of the session period;

generating a secret key at the first transmit/receive unit from the stored public stream of random noise using the random numbers;

generating the same secret key at the second transmit/receive unit by sampling the transmitted public noise stream using the random numbers during the session period; and

transmitting an encrypted stream of data from the first transmit/receive unit to the second transmit/receive unit using the secret key.

20. The method of claim 19 further comprising receiving a second encrypted stream of data at the first transmit/receive unit using the secret key.

21. The method of claim 19 wherein the second transmit/receive unit is a base station.

22. A method of generating an encrypted stream of data comprising:

negotiating, at a first transmit/receive unit, a session period with a second transmit/receive unit;

receiving, at the first transmit/receive unit, a public stream of random noise for the session period, wherein the receiving is performed for a period of time long enough to exceed the storage limit of an eavesdropper;

storing, at the second transmit/receive unit, the public stream of random noise in a storage that is larger than a memory capacity of the eavesdropper;

generating, at the first transmit/receive unit, internal random numbers;

sampling, at the first transmit/receive unit, the public stream of random noise by selectively storing bits from the public stream of random noise based on the random numbers to create a secret key during the session period;

upon completion of the session period, transmitting the internal random numbers from the first transmit/receive unit to the second transmit/receive unit;

generating the same secret key at the second transmit/receive unit by sampling the stored public stream of random noise using the received random numbers; and

transmitting an encrypted stream of data using the secret key from the first transmit/receive unit to the second transmit/receive unit.

23. The method of claim 22 further comprising:

receiving a second encrypted stream of data at the first transmit/receive unit using the secret key.

24. The method of claim 22 wherein the public stream of random noise is received from an entity other than the second transmit/receive unit.