Method for encrypting transmitted data using a unique key
First Claim
1. A method of encrypting data for on-line data communication between a host computer and each of a plurality of remote terminals, wherein a unique dynamic key is periodically generated for each said terminal using a system seed key residing only in the host computer, said dynamic key being for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer, each said terminal further including means for storing a previously generated dynamic key for said terminal, said method comprising the steps of:
- a. receiving at said host computer a new dynamic key request from one of said terminals, said new dynamic key request including a predetermined terminal identifier for said terminal;
b. determining in said host computer the dynamic key previously generated for said terminal by said host wherein said dynamic key previously generated by said host is currently stored in said terminal;
c. generating in said host computer a new dynamic key for said terminal as a function of said seed key and said predetermined terminal identifier for said terminal;
d. encrypting said new dynamic key in said host computer using said dynamic key previously generated by said host computer;
e. transmitting said encrypted new dynamic key from said host computer to said terminal;
f. decrypting said new dynamic key at said terminal using said dynamic key previously generated by said host currently stored in said terminal;
g. encrypting data at said terminal using said new dynamic key and transmitting said encrypted data to said host;
h. decrypting said encrypted data at said host using said new dynamic key; and
i. storing said new dynamic key in said terminal in place of said dynamic key previously generated by said host.
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Accused Products
Abstract
The invention comprises a method for encrypting data for communication between a host computer and each of a plurality of remote terminals in a network. A method is provided for periodically generating a unique dynamic encryption key for each of said plurality of terminals using a system seed key residing only in the host computer. The dynamic encryption key generated for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer. The method includes storing at said terminal the dynamic key previously generated by said host for said terminal.
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Citations
35 Claims
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1. A method of encrypting data for on-line data communication between a host computer and each of a plurality of remote terminals, wherein a unique dynamic key is periodically generated for each said terminal using a system seed key residing only in the host computer, said dynamic key being for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer, each said terminal further including means for storing a previously generated dynamic key for said terminal, said method comprising the steps of:
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a. receiving at said host computer a new dynamic key request from one of said terminals, said new dynamic key request including a predetermined terminal identifier for said terminal; b. determining in said host computer the dynamic key previously generated for said terminal by said host wherein said dynamic key previously generated by said host is currently stored in said terminal; c. generating in said host computer a new dynamic key for said terminal as a function of said seed key and said predetermined terminal identifier for said terminal; d. encrypting said new dynamic key in said host computer using said dynamic key previously generated by said host computer; e. transmitting said encrypted new dynamic key from said host computer to said terminal; f. decrypting said new dynamic key at said terminal using said dynamic key previously generated by said host currently stored in said terminal; g. encrypting data at said terminal using said new dynamic key and transmitting said encrypted data to said host; h. decrypting said encrypted data at said host using said new dynamic key; and i. storing said new dynamic key in said terminal in place of said dynamic key previously generated by said host. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. In a network comprising a host computer and a plurality or remote terminals, a method for safeguarding the on-line transmission of data between said host computer and any one of said plurality of remote terminals wherein a unique encryption key is used for each transmission of data between said host computer and said one of said plurality of terminals, said unique encryption key being derived as function of a unique dynamic key generated using a system seed key residing only in said host computer wherein a plurality of unique dynamic keys may be generated as a function of said seed key, and wherein N is a finite integer greater than or equal to 1 that defines the number of unique dynamic keys generated as a function of said seed key, said generation of said unique dynamic keys being programmable to occur at preselected intervals, comprising the steps of:
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a. generating in said host computer an nth dynamic key for said one of said plurality of terminals, wherein said nth dynamic key is a function of said seed key and a predetermined terminal identifier for said one of said plurality of terminals; b. encrypting said nth dynamic key in said host computer using the (n-1)th dynamic key, wherein said (n-1)th dynamic key is also stored at said one of said plurality of terminals; c. transmitting said encrypted nth dynamic key from said host computer to said one of said plurality of terminals; d. decrypting said nth dynamic key at said terminal using said (n-1)th dynamic key stored at said one of said plurality of terminals; e. encrypting data at said one of said plurality of terminals using said nth dynamic key and transmitting said encrypted data to said host; f. decrypting said encrypted data at said host using said nth dynamic key. - View Dependent Claims (23, 24)
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25. A method of encrypting data for on-line data communication between a host computer and each of a plurality of remote terminals, wherein a unique dynamic key is periodically generated for each said terminal using a system seed key residing only in the host computer, said dynamic key being for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer, each said terminal further including means for storing a previously generated dynamic key for said terminal, said method comprising the steps of:
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a. receiving at said host computer a new dynamic key request from one of said terminals, said new dynamic key request including a predetermined terminal identifier for said terminal; b. determining in said host computer the dynamic key previously generated for said terminal by said host wherein said dynamic key previously generated by said host is currently stored in said terminal; c. generating in said host computer a new dynamic key for said terminal as a function of said seed key and said predetermined terminal identifier for said terminal; d. encrypting said new dynamic key in said host computer using said dynamic key previously generated by said host computer; e. transmitting said encrypted new dynamic key from said host computer to said terminal; f. decrypting said new dynamic key at said terminal using said dynamic key previously generated by said host currently stored in said terminal; - View Dependent Claims (26, 27, 28, 29, 30)
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31. A method of encrypting data for on-line data communication between a host computer and each of a plurality of remote terminals, wherein a unique dynamic key is periodically generated for each said terminal using a system seed key residing only in the host computer, said dynamic key being for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer, each said terminal further including means for storing a previously generated dynamic key for said terminal, said method comprising the steps of:
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a. sending a new dynamic key request to said host computer, said new dynamic key request comprising at least a terminal identification number for said terminal and a terminal transaction number for said terminal; b. receiving from said host computer an encrypted new dynamic key, wherein said new dynamic key is generated as a function of said new dynamic key request and said new dynamic key is encrypted by said host with a previously generated dynamic key; c. decrypting said new dynamic key at said terminal using said dynamic key previously generated by said host currently stored in said terminal; d. encrypting data at said terminal using said new dynamic key and transmitting said encrypted data to said host; e. decrypting said encrypted data at said host using said new dynamic key; and f. storing said new dynamic key in said terminal in place of said dynamic key previously generated by said host. - View Dependent Claims (32, 33, 34, 35)
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Specification