US6408075B1
Expired / Lapsed
US
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Information processing equipment and IC card
Assignee: Hitachi Ltd
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Filing: 2000-03-14
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Granted: 2002-06-18
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Expires: 2020-03-14
Abstract
Abstract An IC card having a storage memory including a program storage unit for storing a program and a data storage unit for storing data and a central processing unit for executing a predetermined process in accordance with the program to process the data, the program including one or more data process units each having a process instruction for giving an execution instruction to the central processing unit, wherein a data process order is randomly exchanged and a dummy process is added to thereby reduce the dependency of consumption current of an IC chip upon the data process.
Inventors
- 👤 Masaru Ohki
- 👤 Yasuko Fukuzawa
- 👤 Susumu Okuhara
- 👤 Masahiro Kaminaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:51
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/002; H04L9/003; G; G06; G06F; G06F7/00; G06F7/60; G06F7/72; G06F7/723; G06F9/00; G06F9/06; G06F9/30; G06F9/38; G06F9/3836; G06F9/3838; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/073; G06K19/07309; G06K19/07363; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/341; G07; G07F; G07F7/00; G07F7/08; G07F7/0806; G07F7/0813; G07F7/082; G07F7/10; G07F7/1008; G06F2207/00; G06F2207/72; G06F2207/7219; G06F2207/7223; G06F2207/7233; G06F2207/7247; G06F2207/7252; G06F2207/7257; G06F7/721; H04L2209/00; H04L2209/08; H04L2209/12; H04L2209/127
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
145 words
An information processing equipment for performing square-and-multiply algorithm calculation, comprising: modular exponentiation means for performing a modular exponentiation using a square; modular multiplication means for performing a modular multiplication using an output of said modular exponentiation means and input data; and modular multiplication result selection means for passing a modular multiplication result to said modular exponentiation means as a number to be squared if a value of a bit of the cipher key is 1, and passing a modular exponentiation result to said modular exponentiation means as a number to be squared if the value of the bit of the cipher key is 0, wherein said modular exponentiation means and the modular multiplication means repetitively operates for all bits of the cipher key, and a number of operations of said modular exponentiation means and the modular multiplication means is independent of the cipher key value.
Claim 2
Dependent Claim
145 words
An information processing equipment for performing square-and-multiply algorithm calculation, comprising: modular exponentiation means for performing a modular exponentiation using a square; modular multiplication means for performing a modular multiplication using an output of said modular exponentiation means and input data; and modular multiplication result selection means for passing a modular multiplication result to said modular exponentiation means as a number to be squared if a value of a bit of the cipher key is 1, and passing a modular exponentiation result to said modular exponentiation means as a number to be squared if the value of the bit of the cipher key is 0, wherein said modular exponentiation means and the modular multiplication means repetitively operates for all bits of the cipher key, and a number of operations of said modular exponentiation means and the modular multiplication means is independent of the cipher key value.
Claim 3
Dependent Claim
16 words
An information processing equipment according to claim 1 , wherein the equipment is an IC card.
Claim 4
Dependent Claim
24 words
An information processing equipment according to claim 2 , wherein the IC card includes a co-processor and the modular multiplication means is the co-processor.
Claim 5
Dependent Claim
117 words
An information processing equipment for performing an addition chain algorithm, comprising: value change means for changing values relating to input data; modular exponentiation means for performing a modular exponentiation; and modular multiplication means for performing a modular multiplication using an output of said modular exponentiation means and changed values output from said value change means, the modular multiplication using one of the changed values depending upon a value of a plurality of successive bits of a cipher key; and passing the modular multiplication result to said modular exponentiation means for next repetition, wherein said value change means, said modular exponentiation means and the modular multiplication means repetitively operate for all sets of bits of the cipher key.
Claim 6
Dependent Claim
117 words
An information processing equipment for performing an addition chain algorithm, comprising: value change means for changing values relating to input data; modular exponentiation means for performing a modular exponentiation; and modular multiplication means for performing a modular multiplication using an output of said modular exponentiation means and changed values output from said value change means, the modular multiplication using one of the changed values depending upon a value of a plurality of successive bits of a cipher key; and passing the modular multiplication result to said modular exponentiation means for next repetition, wherein said value change means, said modular exponentiation means and the modular multiplication means repetitively operate for all sets of bits of the cipher key.
Claim 7
Dependent Claim
33 words
An information processing equipment according to claim 4 , further comprising: inverse means for performing an operation on a final result after all repetition to remove an effect of said value change means.
Claim 8
Dependent Claim
36 words
An information processing equipment according to claim 4 , further comprising: inverse means for performing an operation on the result of the modular multiplication of each repetition to remove an effect of said value change means.
Claim 9
Dependent Claim
36 words
An information processing equipment according to claim 4 , wherein said value change means adds an integer (v) multiple of a modulus (n) in a modular calculation to the values relating to the input data respectively.
Claim 10
Dependent Claim
79 words
An information processing equipment according to claim 5 , wherein said value change means elects two integer values v and u satisfying v*u mod n=1 where n is a modulus in a modular calculation, and performs a modular multiplication using v or v**r where r is an arbitrary integer, and said inverse means performs a modular multiplication using u*s where s is a number of times of the modular multiplication using v or v**r in said value change means.
Claim 11
Dependent Claim
22 words
An information processing equipment according to claim 7 , wherein the selected two integer values v and u are 2 and (n+1)/2.
Claim 12
Dependent Claim
28 words
An information processing equipment according to claim 4 , wherein said modular multiplication means performs a modular multiplication depending on two successive bit values of the cipher key.
Claim 13
Dependent Claim
27 words
An information processing equipment according to claim 7 , wherein said value change means uses 2 to an arbitrary integer power or 2**8 as the integer (v).
Claim 14
Dependent Claim
16 words
An information processing equipment according to claim 4 , wherein the equipment is an IC card.
Claim 15
Dependent Claim
24 words
An information processing equipment according to claim 12 , wherein the IC card includes a co-processor and the modular multiplication means is the co-processor.
Claim 16
Independent Claim
145 words
A method of performing square-and-multiply algorithm calculation in an information processing equipment, comprising: a step (a) of performing a modular exponentiation using a square; a step (b) of performing a modular multiplication using an output of said modular exponentiation step and input data; a step (c) of passing a modular multiplication result to said modular exponentiation step (a) as a number to be squared if the value of a bit of a cipher key is 1, and passing a modular exponentiation result to said modular exponentiation step (a) as a number to be squared if the value of a bit of the cipher key is 0; and a step (d) of repeating said steps (a), (b) and (c) for all bits of the cipher key, wherein a number of the modular exponentiation calculation and the modular multiplication calculation is independent of the cipher key value.
Claim 17
Independent Claim
145 words
A method of performing square-and-multiply algorithm calculation in an information processing equipment, comprising: a step (a) of performing a modular exponentiation using a square; a step (b) of performing a modular multiplication using an output of said modular exponentiation step and input data; a step (c) of passing a modular multiplication result to said modular exponentiation step (a) as a number to be squared if the value of a bit of a cipher key is 1, and passing a modular exponentiation result to said modular exponentiation step (a) as a number to be squared if the value of a bit of the cipher key is 0; and a step (d) of repeating said steps (a), (b) and (c) for all bits of the cipher key, wherein a number of the modular exponentiation calculation and the modular multiplication calculation is independent of the cipher key value.
Claim 18
Independent Claim
112 words
A method of performing addition chain algorithm calculation in an information processing equipment, comprising: a step (a) of changing values relating to input data; a step (b) of performing a modular exponentiation; a step (c) of performing a modular multiplication using an output of said modular exponentiation calculation and the changed values, the modular multiplication using one of the changed values depending on a value of a plurality of successive bits of a cipher key, and passing the modular multiplication result to said modular exponentiation step (b) for the next repetition; and a step (d) of repeating the steps (a), (b) and (c) for all sets of bits of the cipher key.
Claim 19
Independent Claim
112 words
A method of performing addition chain algorithm calculation in an information processing equipment, comprising: a step (a) of changing values relating to input data; a step (b) of performing a modular exponentiation; a step (c) of performing a modular multiplication using an output of said modular exponentiation calculation and the changed values, the modular multiplication using one of the changed values depending on a value of a plurality of successive bits of a cipher key, and passing the modular multiplication result to said modular exponentiation step (b) for the next repetition; and a step (d) of repeating the steps (a), (b) and (c) for all sets of bits of the cipher key.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-06-17 | 2005-12-17 | 2006-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-06-17 | 2009-12-17 | 2010-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-06-17 | 2013-12-17 | 2014-06-18 | $7700.00 | Window Closed / Lapsed |