US6748535B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for suppressing conducted emissions by a cryptographic device comprising an integrated circuit
Assignee: Pitney Bowes Inc
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Filing: 1999-12-09
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Granted: 2004-06-08
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Expires: 2019-12-09
Abstract
Abstract System and method for performing cryptographic operations include providing at least one processor for performing cryptographic operations, memory coupled to the processor for use in performing the cryptographic operations; and a storage component coupled to the processor for storing and retrieving information calculated and used in the cryptographic operations. The processor, memory and storage component are securely enclosed whereby direct access to the cryptographic operations is prevented. At least the processor is comprised in an integrated circuit. A first power source, which is external to the secure enclosure, is coupled to and supplies power to the processor, the memory and the storage component. A second power source, which is within the housing of the integrated circuit, is coupled to and supplies power to at least the processor. A switch is included for switching from the first power source to the second power source when the cryptographic operations are being performed and for switching from the second power source to the first power source when non-cryptographic operations are being performed.
Inventors
- 👤 Frederick W. Ryan, Jr.
- 👤 Monroe A. Weiant, Jr.
- 👤 Edward J. Twarog
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:11
CPC Classifications
G; G07; G07B; G07B17/00; G07B17/00733; G06; G06F; G06F21/00; G06F21/70; G06F21/71; G06F21/72; G06F21/75; G06F21/755; G06F21/81; G07B17/00185; G07B17/00193; G06F2207/00; G06F2207/72; G06F2207/7219; G07B2017/00233; G07B17/00314; G07B2017/00346; G07B2017/00959; G07B2017/00967
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
154 words
A method of limiting conducted emissions by a cryptographic device performing cryptographic operations, said cryptographic device comprising an integrated circuit having a secure housing, said integrated circuit performing at least a portion of said cryptographic operations, the method comprising the steps of: providing power to said integrated circuit from a first power source, said first power source being external to the secure housing locating a second power source within said secure housing for said integrated circuit, said second power source forming part of said integrated circuit; isolating at least a part of said integrated circuit from said first power source during at least a part of said portion of said cryptographic operations; and providing power to said at least a part of said integrated circuit from the second power source at least part of the time when said integrated circuit is performing said at least a part of said portion of said cryptographic operations.
Claim 2
Independent Claim
154 words
A method of limiting conducted emissions by a cryptographic device performing cryptographic operations, said cryptographic device comprising an integrated circuit having a secure housing, said integrated circuit performing at least a portion of said cryptographic operations, the method comprising the steps of: providing power to said integrated circuit from a first power source, said first power source being external to the secure housing locating a second power source within said secure housing for said integrated circuit, said second power source forming part of said integrated circuit; isolating at least a part of said integrated circuit from said first power source during at least a part of said portion of said cryptographic operations; and providing power to said at least a part of said integrated circuit from the second power source at least part of the time when said integrated circuit is performing said at least a part of said portion of said cryptographic operations.
Claim 3
Dependent Claim
74 words
The method of claim 1 wherein the step of providing power includes the steps of: switching at least said part of said integrated circuit from said first power source to said second power source prior to or during said portion of said cryptographic operations; and switching at least said part of said integrated circuit from the second power source to the first power source subsequent to or during said portion of said cryptographic operations.
Claim 4
Dependent Claim
64 words
The method of claim 1 wherein said second power source is a power storage circuit, said power storage circuit storing power from said first power source and providing power to said at least part of said integrated circuit during said at least part of the time when said integrated circuit is performing said at least a part of said portion of said cryptographic operations.
Claim 5
Dependent Claim
35 words
The method of claim 3 wherein said cryptographic operations are divided into a plurality of segments and wherein said second power source stores power from the first power source between alternate ones of said segments.
Claim 6
Dependent Claim
18 words
The method of claim 4 wherein said segments are distributed over said cryptographic operations in a fixed order.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein said segments are distributed over said cryptographic operations in a random order.
Claim 8
Dependent Claim
33 words
The method of claim 3 wherein said part of said integrated circuit includes a row of cells and said power storage circuit is physically located at one end of said row of cells.
Claim 9
Dependent Claim
43 words
The method of claim 3 wherein said part of said integrated circuit includes a row of cells and said power storage circuit includes a plurality of capacitors, each of the plurality of capacitors being located proximate to a corresponding one of said cells.
Claim 10
Dependent Claim
17 words
The method of claim 1 wherein said cryptographic operations generate a digital token for a postal indicium.
Claim 11
Dependent Claim
18 words
The method of claim 1 wherein said cryptographic operations generate a secure message for a value metering system.
Claim 12
Dependent Claim
169 words
A cryptographic system for performing cryptographic operations, comprising: an integrated circuit including a processor for performing cryptographic operations, said integrated circuit having a secure housing; a first power source coupled to and supplying power to said processor, said first power source being external to said secure housing of said integrated circuit; a second power source within the secure housing of said integrated circuit coupled to and supplying power to at least a part of said processor, said second power source forming part of said integrated circuit; and a switch responsive to a power control signal from said processor for switching between said first power source and said second power source, said switch isolating said at least a part of said processor from said first power source and connecting said at least a part of said processor to said second power source, said second power source providing power to said at least a part of said processor when said processor is performing at least a portion of said cryptographic operations.
Claim 13
Dependent Claim
169 words
A cryptographic system for performing cryptographic operations, comprising: an integrated circuit including a processor for performing cryptographic operations, said integrated circuit having a secure housing; a first power source coupled to and supplying power to said processor, said first power source being external to said secure housing of said integrated circuit; a second power source within the secure housing of said integrated circuit coupled to and supplying power to at least a part of said processor, said second power source forming part of said integrated circuit; and a switch responsive to a power control signal from said processor for switching between said first power source and said second power source, said switch isolating said at least a part of said processor from said first power source and connecting said at least a part of said processor to said second power source, said second power source providing power to said at least a part of said processor when said processor is performing at least a portion of said cryptographic operations.
Claim 14
Dependent Claim
15 words
The system of claim 11 wherein said second power source is a power storage circuit.
Claim 15
Dependent Claim
51 words
The system of claim 12 wherein said power storage circuit includes a capacitor, said capacitor being charged at least part of the time and discharged to supply power to said at least a so part of said processor at least part of the time when said cryptographic operations are being performed.
Claim 16
Dependent Claim
30 words
The system of claim 13 wherein said cryptographic operations are divided into a plurality of segments and wherein said power storage circuit is recharged between alternate ones of said segments.
Claim 17
Dependent Claim
18 words
The system of claim 14 wherein said segments are distributed over said cryptographic operations in a fixed order.
Claim 18
Dependent Claim
18 words
The system of claim 14 wherein said segments are distributed over said cryptographic operations in a random order.
Claim 19
Dependent Claim
32 words
The system of claim 13 wherein said part of said processor includes a row of cells and said power storage circuit is physically located at one end of said row of cells.
Claim 20
Dependent Claim
31 words
The system of claim 13 wherein said part of said processor includes a row of cells and a respective capacitor is located proximate to each of said cells in said row.
Claim 21
Dependent Claim
17 words
The system of claim 11 wherein said cryptographic operations generate a digital token for a postal indicium.
Claim 22
Dependent Claim
18 words
The system of claim 11 wherein said cryptographic operations generate a secure message for a value metering system.
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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) | 2007-06-08 | 2007-12-08 | 2008-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-06-08 | 2011-12-08 | 2012-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-06-08 | 2015-12-08 | 2016-06-08 | $7700.00 | Window Closed / Lapsed |