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Timestamp: 2019-10-20 07:01:16
Document Index: 507979080

Matched Legal Cases: ['arty 204', 'arty 302', 'arty 202', 'arty 202', 'arty 302', 'arty 302', 'arty 202', 'arty 302', 'arty 202', 'arty 302', 'arty 202', 'arty 302']

ASYMMETRIC KEY CRYPTOSYSTEM BASED ON SHARED KNOWLEDGE - Beeson, Curtis Linn
United States Patent Application 20060153364
An asymmetric key cryptosystem is provided using a private key of a public-private key pair by: identifying domain parameters of a finite cyclic group, the domain parameters including an initial generating point; transforming the initial generating point into a new generating point as a deterministic function; generating the public key as a deterministic function of the private key and the domain parameters, in which the new generating point is substituted for the initial generating point; and generating the digital signature as a deterministic function of the private key and the domain parameters, in which the new generating point is substituted for the initial generating point.
11/161555
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1. In a method including the steps of, (a) identifying domain parameters that define a finite cyclic group, the domain parameters including a generating point, and (b) performing a cryptographic operation as a deterministic function that is based upon the domain parameters, an improvement comprising the steps of, (c) transforming the generating point into another member of the finite cyclic group as a deterministic function of shared knowledge, and (d) substituting said transformed generating point of said step (c) for said identified generating point of said step (a) in the deterministic function of said step (b).
2. The method of claim 1, wherein said step of transforming the generation point of said step (c) comprises the steps of generating a large integer value from a deterministic function of the shared knowledge and performing scalar multiplication of the generating point by said generated large integer value.
3. The method of claim 1, further comprising the step of clearing from the computer system the new generating point following said step of generating the digital signature so that the generating point is no longer available within the computer system for regenerating the digital signature.
4. The method of claim 1, wherein the deterministic function of said step (b) comprise a deterministic function for generating a public key of a public-private key pair.
5. The method of claim 1, wherein the deterministic function of said step (b) comprise a deterministic function for generating a digital signature.
6. The method of claim 1, wherein the shared knowledge is known to both a first party and a second party different from the first party.
7. The method of claim 6, wherein the shared knowledge comprises an account number for an account of the first party that is maintained with the second party.
8. The method of claim 6, wherein the shared knowledge comprises information that is communicated between the first party and the second party.
9. The method of claim 6, wherein the shared knowledge comprises information that is communicated by a third party both to the first party and the second party.
10. The method of claim 6, wherein the shared knowledge comprises a unique identifier of the first party to the second party.
11. The method of claim 6, wherein the shared knowledge comprises a deterministic function of one or more predefined arguments, wherein the deterministic function and predefined arguments are known both to the first party and the second party, whereby both the first party and the second party may independently calculate the shared knowledge for use in generating the transformer.
12. The method of claim 6, wherein the shared knowledge is input by the first party into a computer system that performs said step (c) of transforming the generating point.
13. Them method of claim 6, wherein said step of identifying the domain parameters of an elliptic curve comprises receiving an identification of the domain parameters from the second party.
14. The method of claim 6, wherein said step of identifying the domain parameters of an elliptic curve comprises selecting the domain parameters by the first party, and wherein the method further comprises the step of communicating by the first party said selected domain parameters to the second party.
15. The method of claim 1, wherein said deterministic function of said step (b) includes as an argument thereof a private key utilized in public-private key cryptography.
16. The method of claim 2, wherein the private key is generated as a deterministic function of user input data.
19. The method of claim 16, further comprising the step of clearing the user input data from the computer system following said step of generating the private key so that the user input data must be received again within the computer system in order to regenerate the private key within the computer system.
20. The method of claim 16, further comprising the step of clearing the private key from the computer system following said step of generating the digital signature so that the private key must be regenerated within the computer system in order to generate a digital signature within the computer system using the deterministic function of said step (c).
21. The method of claim 15, wherein the private key is generated as a nondeterministic function of a random number generator.
22. A method including the steps of, (a) transforming an initial generating point of domain parameters that define a finite cyclic group into another member of the finite cyclic group as a deterministic function of shared knowledge, and (b) performing a cryptographic operation as a deterministic function that is based upon the domain parameters, wherein said transformed generating point of said step (a) is substituted for the initial generating point of the domain parameters.
23. A computer-readable medium having computer-executable instructions for performing the steps comprising: (a) transforming an initial generating point of domain parameters that define a finite cyclic group into another member of the finite cyclic group as a deterministic function of shared knowledge, and (b) performing a cryptographic operation as a deterministic function that is based upon the domain parameters, wherein said transformed generating point of said step (a) is substituted for the initial generating point of the domain parameters.
1. U.S. Patent Application “PROVIDING DIGITAL SIGNATURE AND PUBLIC KEY BASED ON SHARED KNOWLEDGE” filed on Aug. 8, 2005;
Additionally, it is important to note that each term used herein refers to that which a person skilled in the art would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—understood by a person skilled in the art based on the contextual use of such term-differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by a person skilled in the art should prevail.
Upon receipt of the information from the second party 204 regarding the public key, the third party 302 may evaluate this information in gauging the risk that either the private key utilized to generate the digital signature was compromised and that the message was not, in fact, sent from the first party 202, or that the message was altered while in transit from the first party 202 to the third party 302. Indeed, a risk level can be assigned and taken under consideration in making a business judgment as to whether—and what-action to take, if any, in response by the third party 302 to receipt of a digitally signed message from the first party 202. The third party 302 further may request this information upon further receipt of digital signatures from the first party 202, or the third party 302 may itself record this information in association with the public key of the first party 202 in a database of the third party 302.
Next, a deterministic function is defined that will turn a word, sentence, or any string of characters into a value suitable as a replacement for the random angle value. One example of a deterministic function is to cumulate the numerical values of the characters of an input string the word “PassWord”), divide by a predetermined number (e.g. 360), and use the remainder of the division operation as an angle value. Such an exemplary deterministic function would be expressed as follows in conceptual terms:
The function for generating the digital signature preferably includes appending the indicator to that which is digitally signed such as, for example, an electronic message. The indicator may comprise, for example, either a “1 I” or “0 ” appended to the beginning or end of the electronic message. Of course, the indicator also should be communicated to the recipient of that which was digitally signed in order for the recipient to be able to verify the digital signature; however, the indicator need not be communicated if the recipient is aware of the possible values of the indicator and, therefore, can verify the digital signature by checking all possibilities. For example, the recipient of the electronic message and digital signature for the message-which in this case is the digital signature of both the message and the indicator appended thereto-can append the known different possible values of the indicator to the electronic message in verifying the digital signature. One of the different possibilities should result in verification of the digital signature, provided that the message was not changed in transit and that the true private key was used in generating the digital signature.
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