Method for point-to-point communications within secure communication systems

• US 5,357,571 A
• Filed: 07/01/1993
• Issued: 10/18/1994
• Est. Priority Date: 07/01/1993
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Banwart, Dean E.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/084,119
• Time in Patent Office: 474 Days
• Field of Search: 380/9, 380/21, 380/29, 380/43, 380/45, 380/49, 380/50, 380/20, 380/48
• US Class Current: 380/271
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04W 12/041 Key generation or derivation

Abstract

In a secure communication system, a secure point-to-point communication may be accomplished in the following manner. A first communications unit receives a request from an operator for a point-to-point communication identifying at least one destination communication unit. In response, the first communication unit generates a private call key variable by modifying an encryption key variable through the use of a predetermined function. Identity of the encryption key variable and information pertaining to the predetermined function is transmitted by the first communication unit to the destination communication unit. Upon receiving the identity of the encryption key variable and information pertaining to the predetermined function, the destination communication unit generates the private call key variable. When the private call key variable has been determined by the first communication unit and the destination communication unit, both communication units can engage in the secure point-to-point communication.

Claims

1. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication, units stores a limited set of encryption key variables, a method for providing a point-to-point communication within the secure communication system, the method comprises the steps of:

a) receiving, by a first communication unit of the plurality of communication units, a request for the point-to-point communication from an operator of the first communication unit, wherein the request identifies at least one destination communication unit;

b) generating, by the first communication unit, a private;

call key variable by modifying an encryption key variable of the limited set of encryption key variables based on a predetermined function;

c) transmitting, by the first communication unit to the at least one destination communication unit, identity of the encryption key variable and information pertaining to the predetermined function;

d) generating, by the at least one destination communication unit, the private call key variable based on the encryption key variable and the information pertaining to the predetermined function; and

e) privately communicating between the first communication unit and the at least one destination communication unit using the private call key variable.

2. In the method of claim 1, step (b) further comprises generating the, private call key variable by modifying the encryption key variable based on the predetermined function, wherein the predetermined function includes, at least in part, using a unique identification code of the first communication unit, a unique identification code of the at Least one destination communication unit, or a combination of the unique identification code of the first communication unit and the unique identification code of the at least one destination communication unit to modify the encryption key variable.

3. In the method of claim 2, step (c) further comprises transmitting identity of the encryption key variable and information pertaining to the predetermined function, wherein the information pertaining to the predetermined function includes, in part, the unique identification code of the first communication unit, the unique identification code of the at least one destination communication unit, or the combination of the unique identification code of the first communication unit and the unique identification code of the at least one destination communication unit.

4. In the method of claim 2, the predetermined function further comprises utilizing unique user code to produce the private call key variable.

5. In the method of claim 1, step (d) further comprises identifying, by the at least one destination communication unit, type of the predetermined function such that the private call key variable is generated.

6. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication units stores a limited set of encryption key variables, a method for providing a point-to-point communication within the secure communication system, the method comprises the steps of:

a) receiving, by a first communication unit of the plurality of communication units, a request for a point-to-point communication from an operator Of the first communication unit, wherein the request identifies at least one destination communication unit;

b) generating, by the first communication unit, a private call key variable by modifying an encryption key variable of the limited set of encryption key variables based on a predetermined function;

c) transmitting, by the first communication unit, encrypted information, wherein the encrypted information is, at least in part, encrypted with the private call key variable;

d) receiving, by the plurality of communication units, the encrypted information;

e) decrypting, by each unit of the plurality of communication units, the encrypted information based on a stored predetermined function and unique communication unit information; and

f) when the decrypting of step (e) is successful, communicating, by at least one of the plurality of communication units, with the first communication unit using the private call key variable.

7. In the method of claim 6, step (b) further comprises generating the private call key variable by modifying the encryption key variable based on the predetermined function, wherein the predetermined function includes, at least in part, using a unique identification code of the first communication unit, a unique identification code of the at least one destination communication unit, or a combination of the unique identification code of the first communication unit and the unique identification code of the at least one destination communication unit to modify the encryption key variable.

8. In the method of claim 6, step (e) further comprises identifying, by each of the plurality of communication units, type of the predetermined function such that the private call key variable is generated.

9. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication units stores a limited set of encryption key variables, a method for a communication unit of the plurality of communication units to participate in a point-to-point communication within the secure communication system, the method comprises the steps of:

a) when initiating the point-to-point communication, receiving, by the communication unit, a request for a point-to-point communication from an operator of the communication unit, wherein the request identifies at least one destination communication unit;

b) when initiating the point-to-point communication, generating, by the communication unit, a private call key valuable by modifying an encryption key variable of the limited set of encryption key variables based on a predetermined function;

c) when initiating the point-to-point communication, transmitting, by the communication unit to the at least one destination communication unit, identity of the encryption key valuable and information pertaining to the predetermined function;

d) when acting as a destination communication unit in the point-to-point communication, receiving, by the communication unit, identity of the encryption key variable and the information pertaining to the predetermined function, wherein the identity of the encryption key variable and information pertaining to the predetermined function have been transmitted by a transmitting communication unit;

e) when acting as the destination communication unit in the point-to-point communication, generating, by the communication unit, the private call key variable based on the encryption key variable and the information pertaining to the predetermined function; and

f) when acting as the destination communication unit in the point-to-point communication, privately communicating between the communication unit and the transmitting communication unit.

10. In the method of claim 9, step (b) further comprises generating the private call key variable by modifying the encryption key variable based on the predetermined function, wherein the predetermined function includes, at least in part, using a unique identification code of the communication unit, a unique identification code of the at least one destination communication unit, or a combination of the unique identification code of the communication unit and the unique identification code of the at least one destination communication unit to modify the encryption key variable.

11. In the method of claim 10, step (c) further comprises transmitting identity of the encryption key variable and information pertaining to the predetermined function, wherein the information pertaining to the predetermined function includes, in part, the unique identification code of the communication unit, the unique identification code of the at least one destination communication unit, or the combination of the unique identification code of the communication unit and the unique identification code of the at least one destination communication unit.

12. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication units stores a limited set of encryption key variables, a method for a communication unit of the plurality of communication units to receive a point-to-point communication within the secure communication system, the method comprises the steps of:

a) receiving, by the communication unit, identity of an encryption key variable and information pertaining to a predetermined function, wherein the identity of the encryption key variable and information pertaining to the predetermined function have been transmitted by a transmitting communication unit;

b) generating, by the communication unit, a private call key variable based on the encryption key variable and the information pertaining to the predetermined function; and

c) utilizing the private call key variable to privately communicate with the transmitting communication unit.

13. In the method of claim 12, step (b) further comprises generating the, private call key variable by modifying the encryption key variable based on information pertaining to the predetermined function, wherein the information pertaining to the predetermined function includes, at least in part, a unique identification code of the communication unit, a unique identification code of the transmitting communication unit, or a combination of the unique identification code of the communication unit and the unique identification code of the transmitting communication unit.

14. The method of claim 13 further comprises identifying, by the communication unit, type of the predetermined function such that the private call key variable is generated.

15. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication units stores a limited set of encryption key variables, a method for a communication unit of the plurality of communication units to participate in a point-to-point communication within the secure communication system, the method comprises the steps of:

a) when initiating the point-to-point communication, receiving, by the communication unit, a request for a point-to-point communication from an operator of the communication unit, wherein the request identifies at least one destination communication unit;

b) when initiating the point-to-point communication, generating, by the communication unit, a private call key variable by modifying an encryption key variable of the limited set of encryption key variables based on a predetermined function;

c) when initiating the point-to-point communication, transmitting, by the communication unit, encrypted information, wherein the encrypted information is, at least in part, encrypted with the private call key variable;

d) when acting as a destination communication unit in the point-to-point communication, receiving, by the communication unit, encrypted information, wherein the encrypted information has been encrypted using the private call key variable by a transmitting communication unit;

e) when acting as the destination communication unit in the point-to-point communication, decrypting, by the communication unit the encrypted information i based on a stored predetermined function and unique communication unit information and

f) when acting as the destination communication unit in the point-to-point communication, when the decanting of step (e) is successful, communicating, by the communication unit, with the transmitting communication unit using the private call key variable.

16. In the method of claim 15, step (b) further comprises generating the private call key variable by modifying the encryption key variable based on the predetermined function, wherein the predetermined function includes, at least in part, using a unique identification code of the communication unit, a unique identification code of the at least one destination communication unit, or a combination of the unique identification code of the communication unit and the unique identification code of the at least one destination communication unit to modify the encryption key variable.

17. In a secure communication system that includes a plurality of communication units, wherein each communication unit of the plurality of communication units stores a limited set of encryption key variables, a method for a communication unit of the plurality of communication units to receive a point-to-point communication within the secure communication system, the method comprises the steps of:

a) receiving, by the communication unit, encrypted information, wherein the encrypted information has been encrypted using a private call key variable by a transmitting communication unit;

b) decrypting, by the communication unit, the encrypted information based on a stored predetermined function and unique communication unit information; and

c) when the decrypting of step (b) is successful, communicating, by the communication unit, with the transmitting communication unit using the private call key variable.

18. In the method of claim 17, step (b) further comprises identifying, by the communication unit, type of the predetermined function such that the private call key variable is generated.