U.S. patent application number 17/225941 was filed with the patent office on 2021-08-05 for physical unclonable functions in integrated circuit chip packaging for security.
The applicant listed for this patent is Lexmark International, Inc.. Invention is credited to Stephen P. Bush, Gary A. Denton, James Paul Drummond, Kelly Ann Killeen, Carl E. Sullivan.
Application Number | 20210242141 17/225941 |
Document ID | / |
Family ID | 1000005526898 |
Filed Date | 2021-08-05 |
United States Patent
Application |
20210242141 |
Kind Code |
A1 |
Bush; Stephen P. ; et
al. |
August 5, 2021 |
Physical Unclonable Functions in Integrated Circuit Chip Packaging
for Security
Abstract
In the invention described, magnetic field characteristics of
randomly placed magnetized particles are exploited by using the
magnetic field fluctuations produced by the particles as measured
by a sensor. The magnetized particles generate a complex magnetic
field near the surface of an integrated circuit chip that can be
used as a "fingerprint." The positioning and orientation of the
magnetized particles is an uncontrolled process, and thus the
interaction between the sensor and the particles is complex. The
randomness of the magnetic field magnitude and direction near the
surface of the material containing the magnetic particles can be
used to obtain a unique identifier for an item such as an
integrated circuit chip carrying the PUF.
Inventors: |
Bush; Stephen P.; (Richmond,
KY) ; Denton; Gary A.; (Lexington, KY) ;
Drummond; James Paul; (Georgetown, KY) ; Killeen;
Kelly Ann; (Lexington, KY) ; Sullivan; Carl E.;
(Stamping Ground, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lexmark International, Inc. |
Lexington |
KY |
US |
|
|
Family ID: |
1000005526898 |
Appl. No.: |
17/225941 |
Filed: |
April 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15808573 |
Nov 9, 2017 |
|
|
|
17225941 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 23/29 20130101;
H01L 23/57 20130101; H01L 23/3107 20130101; H01L 24/46 20130101;
H01L 24/06 20130101; H01L 23/49541 20130101; H04L 9/3278 20130101;
H01L 2224/04042 20130101; H01L 23/573 20130101 |
International
Class: |
H01L 23/00 20060101
H01L023/00; H04L 9/32 20060101 H04L009/32; H01L 23/29 20060101
H01L023/29; H01L 23/31 20060101 H01L023/31 |
Claims
1. A system comprising: a substrate; a plurality of pre-magnetized
particles that have random orientations of magnetization and are
randomly dispersed in the substrate; an external magneto-resistive
sensor, wherein a magnetic field profile is measured along a
defined non-linear path by relative movement of the sensor and the
substrate; and an integrated circuit chip.
2. The system of claim 1, further comprising a non-volatile memory
on the integrated circuit chip, wherein the non-volatile memory
contains magnetic field profile data measured from the
pre-magnetized particles.
3. The system of claim 1, wherein the pre-magnetized particles
contain neodymium and iron and boron.
4. The system of claim 1, wherein the pre-magnetized particles
contain samarium and cobalt.
5. The system of claim 1, wherein the average particle size
diameter of the pre-magnetized particles is greater than 0.1
mm.
6. The system of claim 1, wherein the average particle size
diameter of the pre-magnetized particles is greater than 0.001 mm.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/808,573 titled "Physical Unclonable
Functions in Integrated Circuit Chip Packaging for Security," filed
on Nov. 9, 2017.
BACKGROUND
1. Field of the Disclosure
[0002] The present disclosure relates generally to anti-counterfeit
systems and more particularly to physical unclonable functions.
2. Description of the Related Art
[0003] Counterfeit integrated circuit chips ("ICCs") are a major
concern in the electronic component supply industry because of
reliability and security issues. Such counterfeit ICCs are
impacting many industrial sectors, including computers, printing,
telecommunications, automotive electronics, medical, banking,
energy/smart-grid, aerospace, and military systems. The
consequences can be dramatic when critical systems begin to fail or
act maliciously due to the use of counterfeit or low-quality
components causing minor, major, or mission failures, including
health or safety concerns.
[0004] The National Defense Authorization Act (NDAA) of 2012, for
example, is focused on defense contractors who do not screen their
equipment for counterfeit parts. There can be civil and criminal
liability for contractors who do not eliminate counterfeit
electronic parts in military equipment, according to the Forbes
article, "NDAA May Put Defense Contractors In Prison For
Counterfeit Parts," Feb. 14, 2012.
[0005] The tools and technologies utilized by counterfeiters have
become extremely sophisticated and well financed. In turn, this
also calls for more sophisticated methods to detect counterfeit
electronic parts that enter the market. Hardware intrinsic security
is a mechanism that can provide security based on inherent
properties of an electronic device. A physical unclonable function
("PUF") belongs to the realm of hardware intrinsic security.
[0006] In the printer industry, counterfeit printer supplies
including ICCs are a problem for consumers. Counterfeit supplies
may perform poorly and may damage printers. Printer manufacturers
use authentication systems to deter counterfeiters. PUFs are a type
of authentication system that implements a physical one-way
function. Ideally, a PUF cannot be identically replicated and thus
is difficult to counterfeit. Incorporating a PUF in electronic
device packaging, including ICCs, deters counterfeiters.
SUMMARY
[0007] In the invention described, magnetic field characteristics
of randomly placed magnetized particles are exploited by using the
magnetic field fluctuations produced by the particles as measured
by a sensor, such as a Hall-effect sensor, or an array of such
sensors. The invention consists of an ICC encased in or over-molded
by a substrate that contains magnetic particles. The magnetized
particles generate a complex magnetic field near the surface of the
ICC that can be used as a "fingerprint." The positioning and
orientation of the magnetized particles is an uncontrolled process,
and thus the interaction between the sensor and the particles is
complex. Thus, it is difficult to duplicate the device such that
the same magnetic pattern and particle physical location pattern
will arise. The randomness of the magnetic field magnitude and
direction near the surface of the material containing the magnetic
particles can be used to obtain a unique identifier for an item
such as an integrated circuit chip carrying the PUF. Further, the
placement of the device in the top layer of an integrated circuit
chip protects the underlying circuits from being inspected by an
attacker, e.g., for reverse engineering. When a counterfeiter
attempts to remove all or a portion of the coating, the magnetic
field distribution must change, thus destroying the original unique
identifier.
[0008] The invention, in one form thereof, is directed to an
integrated circuit chip overlain or encapsulated by a PUF
comprising randomly placed magnetic particles.
[0009] The invention, in another form thereof, is directed to an
integrated circuit chip used in a printer or printer supply
component, such as a toner cartridge, that is overlain or
encapsulated by a PUF comprising randomly placed magnetic
particles.
[0010] The invention, in yet another form thereof, is directed to
an EMV (Europay, Mastercard, Visa) transaction chip or embedded
microchip on a bank card overlain by a PUF comprising randomly
placed magnetic particles.
[0011] The invention, in yet another form thereof, is directed to
an apparatus having an EMV transaction chip mounted on substrate
that forms the body of a bank card, where a plurality of magnetized
particles are dispersed in the substrate to form a PUF.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings incorporated in and forming a part
of the specification, illustrate several aspects of the present
disclosure, and together with the description serve to explain the
principles of the present disclosure.
[0013] FIG. 1 is a view of an integrated chip.
[0014] FIG. 2 is a view of an integrated chip with magnetized
particles molded into the housing.
[0015] FIG. 3 is a view of an integrated chip with an array of
sensors formed above the chip with magnetized particles molded into
the housing.
[0016] FIG. 4 is an orthogonal view of a substrate containing
magnetic and non-magnetic particles.
[0017] FIG. 5 is a side view of a PUF and PUF readers.
[0018] FIG. 6 is a view of the front of a bank card with an EMV
transaction chip.
[0019] FIG. 7 is a view of the back of a bank card with a magnetic
strip.
[0020] FIG. 8 is a bank card chip reader device.
[0021] FIG. 9 is an end view of the bank card chip reader
device.
[0022] FIG. 10 is a flowchart of a method of making a secure
device.
[0023] FIG. 11 is a magnetic field profile along a defined
path.
[0024] FIGS. 12a, 12b, and 12c are three-dimensional
representations of the magnetic flux density measured across the
area resolved into three coordinate components, B.sub.x, B.sub.y,
and B.sub.z.
DETAILED DESCRIPTION
[0025] In the following description, reference is made to the
accompanying drawings where like numerals represent like elements.
The embodiments are described in sufficient detail to enable those
skilled in the art to practice the present disclosure. It is to be
understood that other embodiments may be utilized and that process,
electrical, and mechanical changes, etc., may be made without
departing from the scope of the present disclosure. Examples merely
typify possible variations. Portions and features of some
embodiments may be included in or substituted for those of others.
The following description, therefore, is not to be taken in a
limiting sense and the scope of the present disclosure is defined
only by the appended claims and their equivalents.
[0026] Referring now to the drawings and particularly to FIG. 1,
when an ICC 1001 is manufactured, it is typically packaged by being
attached to a metal lead frame 1008 that is connected to solder
pads 1002 and 1003 by a wire bonds 1004 and 1005, and then enclosed
in an encapsulant 1006 which is then cured. The encapsulated chip
is then molded into a plastic housing 1007.
[0027] Referring now to FIG. 2, in one embodiment of the invention,
the molded plastic housing 1007 is replaced with the molded plastic
housing or substrate 2007 where dispersed in the substrate is a
plurality of magnetized particles 4014. The particles are
distributed randomly such that it is extremely difficult to
reproduce the exact distribution and alignment of particles.
Preferably, the particles are magnetized before dispersion in the
substrate to add further randomness to the resulting magnetic field
profile. Thus, the substrate 2007 and the particles 4014 form a
physical unclonable function out of the molded plastic housing.
[0028] The magnetic field profile near the surface of the ICC may
be measured by an external magneto-resistive sensor (not shown), a
Hall-effect sensor (not shown), or an array of such sensors, in
close proximity to the top surface of the ICC. Since the sensing
elements are typically around 0.3-0.5 mm below the surface of the
sensing device, the average particle size diameter using
Hall-effect sensor or magneto-resistive sensor is preferably
greater than 0.1 mm. Note that the diameter of a non-spherical
particle is the diameter of the smallest sphere that encloses the
particle. Other sensor options include magneto-optical sensor
technology, which is capable of working with smaller magnetic
particle sizes, but is more costly to implement and subject to
contamination problems.
[0029] The magnetic field profile measurements may be taken within
a defined area or along a defined path: straight, circular, or any
arbitrarily selected and defined path, and recorded at the ICC
foundry. FIG. 11 shows a magnetic field profile along a defined
path where the magnetic flux density has been resolved into three
coordinate components B.sub.x, B.sub.y, and B.sub.z. FIG. 12 shows
a magnetic field profile measured over a rectangular area as would
be exhibited by the defined area overlaying an ICC. The profile is
a three-dimensional representation of the magnetic flux density
measured across the area. The magnetic flux density vector has been
resolved into three coordinate components, B.sub.x, B.sub.y, and
B.sub.z, shown separately in FIGS. 12a, 12b, and 12c. The magnetic
field profile data would be signed by a private key and written to
the ICC's non-volatile memory ("NVM") during programming. After
installation of the ICC onto a circuit card, the magnetic
"fingerprint" is once again read by an external magneto-resistive
sensor and the magnetic profile is compared to the values stored on
the chip to authenticate the ICC. This system would make it very
difficult for counterfeit ICCs to make their way into high value
applications. The system would be fairly inexpensive to implement
with almost instantaneous authentication of the PUF over-molded
ICCs.
[0030] Referring now to FIG. 3, in a second embodiment of the
invention, the use of magnetized particles 4014 creates a unique
magnetic fingerprint that can be applied to the manufacture of ICCs
by over-molding the encapsulated chip 1001 with a substrate
containing magnetized particles 2007. The term "over-molded" is
used here broadly to mean anything from adding a partial surface
layer over the ICC to completely encasing the ICC. One or more
sensors, such as a Hall-effect sensor 3001 is formed above the chip
body and encased within the housing 2007. In this embodiment, the
sensor(s) 3001 can record a series of analog magnetic intensity
readings, in various locations along the substrate, in one, two, or
three coordinate directions. Such an "internal" Hall-effect sensor
can measure average particle size diameters that are less than 0.1
mm. Since these measurements are analog voltages, with a sufficient
number of measurements and sufficient analog to digital resolution,
unique values can be derived from the measurements. These values
can be used for private keys, seeds, etc. which are not stored in
the device's memory. Instead, they are read and derived by the
device "in flight" (i.e., during operation), thus rendering
ineffective any probing attacks by counterfeiters on the chip
itself. If a counterfeiter were to attempt to extract the private
key from the ICC, it is highly probable that the over-molded
magnetic layer will be disturbed and the private key would be
lost.
[0031] These embodiments may, for example, be implemented on an
integrated circuit chip on a printer or printer supply component,
such as a toner cartridge, that is used to authenticate the toner
cartridge for whatever purpose, as well as to perform other
functions such as toner level monitoring, sheet count, etc.
[0032] A third embodiment of the invention is the application of
the PUF authentication technology to bank cards and identification
cards with an EMV transaction chip. Bank cards 6001, for example,
are under constant attack by counterfeiters. For this reason an EMV
transaction chip 6002 mounted on a substrate 6003 that replaced the
easily counterfeited magnetic strip 7001 shown in FIG. 7, the back
of the bank card 6001. To avoid fraud, the EMV transaction chip may
be used with a personal identification number ("PIN"), but many
cards lack this extra protection for convenience of the customer,
to reduce data requirements in transactions, and to avoid software
upgrades for the PIN operation.
[0033] Bank cards with EMV transaction chips are mostly used in a
contact-based form: the card is inserted into a reader, which
creates a circuit that allows handshaking between the card and the
payment terminal. A unique transaction is created that involves
cryptographic data embedded in the chip.
[0034] For cards that require PINs, the transaction can't be
completed without the code, which is not transmitted remotely as
with debit and ATM transactions. Some cards are equipped with
near-field communications (NFC) radios for contactless EMV
transaction, and will work with point-of-sale systems.
[0035] A unique magnetic PUF signature of the analog magnetic
intensity readings could replace the PIN requirement to
authenticate the bank card. The PUF signature would be a second
factor authentication for the bank card.
[0036] The substrate of a bank card may be fabricated where
dispersed in the substrate is a plurality of magnetic particles.
The particles are distributed randomly such that it is extremely
difficult to reproduce the exact distribution and alignment of
particles. Thus, the substrate and the particles of the bank card
form a physical unclonable function. The magnetic field profile may
be measured by an external sensor, such as a Hall-effect sensor
(not shown) in close proximity to the bank card surface. Other
sensor options include magneto-optical sensor technology. The
magnetic field profile measurements may be taken within a defined
area or along a defined path: straight, circular, or any
arbitrarily selected and defined path, and recorded during
manufacture of the bank card. The magnetic field profile data would
be written to the EVM transaction chip's non-volatile memory.
[0037] When inserted into a card reader 8001, the reader could
sweep a sensor arm across a portion of the bank card and one or
more sensors, such as Hall-effect sensors, located on the sensor
arm would measure the magnetic field in a defined area or along the
defined path. A simple mechanical configuration with a drive cam
would determine the path of the sensor arm sweep. Alternatively, as
shown in FIG. 9, the sensor or sensor array could be at a fixed
location where the bank card slides across the sensors 8003, 8004,
8005, and 8006 as the bank card is inserted into the reader slot
8002. Data corresponding to the magnetic intensity readings along
the sensing path stored in the EMV transaction chip's non-volatile
memory and used to validate the magnetic "fingerprint" detected by
the card reader at time of the transaction. This invention does not
require the user to remember a PIN, and the card reader can perform
the validation locally. Alternatively, the card reader could be
configured to transmit the magnetic "fingerprint" to the bank card
company server or cloud location for remote authentication when
high value transactions are taking place. Data that is stored in a
cloud location is stored in an accessible network such as the
Internet on physical storage devices such as computer servers and
storage networks.
[0038] As an added layer of security, the EMV transaction chip on
the card could contain information that would guide the card reader
to read the magnetic "fingerprint" in a specific location on the
bank card. This location could be different for different cards and
would add yet another layer of complexity to the task of
counterfeiting a bank card. A varying position of the magnetic
"fingerprint" could also be configured to act as a rotating
encryption key. This rotating key could change on a daily, weekly,
or monthly basis. The rotating key could be as simple as two keys
in which data is read off the "fingerprint" in a forward or reverse
motion, which would be the least disruptive to current card reader
configurations. Known algorithms could be utilized to determine
when the "fingerprint" rotates.
[0039] In another embodiment, the bank card substrate to which the
EMV transaction chip is mounted could be the location of a magnetic
"fingerprint" such that removal or alteration of the EMV
transaction chip would distort the substrate and thus alter the
magnetic "fingerprint," rendering the authentication inoperable. In
a further embodiment, the bank card could be implemented in such a
way as to cause tearing to the fingerprint if the chip is
removed.
[0040] The card reader may initiate the bank card authentication by
sending a request to the EMV transaction chip on the bank card for
data. The bank card EMV transaction chip may challenge the card
reader and wait for a proper response (authenticating the reader)
before the bank card security chip transmits the magnetic
"fingerprint" authentication data to the reader. This challenge and
response protocol makes it more difficult for counterfeiters to
acquire data from the bank card. In addition to using the magnetic
"fingerprint" or signature of the bank card, capacitive sensing
technology may be used to detect the presence of the randomly
distributed magnetized particles in the bank card, which could
provide yet another authentication step for validating the bank
card.
[0041] If at least one face of the bank card is non-opaque, the
presence of the magnetized particles could be detected optically by
a digital camera chip or by an optical sensor. Similar to
capacitive sensing, this could provide an additional authentication
step for the bank card.
[0042] This technology could also be used in the same manner
described above to authenticate access badges for secure
facilities, or for other applications such as passports, government
identification cards, driver licenses, etc. The PUF technology
could stand alone as a security device, or in combination with a
integrated circuit chip on the identification card or other
security device having non-volatile memory.
[0043] FIG. 4 shows a region of a substrate 4010. Dispersed in the
substrate is a plurality of magnetized particles 4014. The
particles are distributed randomly such that it is extremely
difficult to reproduce the exact distribution and alignment of
particles. Thus, the substrate 4010 and the particles 4014 form a
PUF.
[0044] FIG. 5 shows a side view of the substrate 4010 containing
the magnetized particles 4014.
[0045] The field data may be measured while moving the PUF relative
to a stationary magnetic field sensor(s) 5001, 5002, 5003 or by
moving the magnetic field sensor(s) 5001, 5002, 5003 next to a
stationary PUF, etc. The sensors are shown in varying orientations,
but such a varied orientation is not necessary. Multiple sensors
may be used to reduce the movement and time required to measure the
magnetic field over a desired area.
[0046] FIG. 10 shows an example of a method of making a secure
device, such as an integrated circuit chip with a PUF overlay or a
bank card with an EMV transaction chip with a PUF substrate.
[0047] The magnetizable particles may be of any shape, and may
contain neodymium and iron and boron. Alternatively, the
magnetizable particles may contain samarium and cobalt. Preferably,
the magnetized particles generate a sufficiently strong magnetic
field to be detected with a low-cost detector.
[0048] Suitable substrate materials are used that allow formed
aggregate pellets of the substrate material and particles to be
magnetized. The magnetizable particles are magnetized by, for
example, subjecting the pellets to a strong magnetic field. After
magnetization, the magnetic particles do not clump together because
the pellet carrier material is a solid. During the molding process,
the pellets are heated and melted prior to molding.
[0049] The substrate carrier is then solidified in an ICC,
overlaying an ICC, encasing an ICC, in the body of a bank card, or
in the section of a bank card beneath the section of a bank card
beneath the position of an EVM transaction chip. In an alternate
embodiment the carrier may be, for example, a liquid that is caused
to become solid by adding a chemical, subjecting to ultraviolet
light, increasing its temperature, etc. Causing the carrier to
become solid locks the distribution and orientation of the
particles. In this case a high viscosity liquid is preferred so
that the particles may be magnetized shortly before the material is
molded. The high viscosity retards the movement of the magnetic
particles toward each other while the material is in a liquid state
and minimizes clumping of the magnetized particles. Clumping could
cause failures of the over-molding process.
[0050] Magnetizing the particles in pellet form yields a more
random magnetic field pattern, and is therefore more difficult to
clone. Further, the application of a magnetizing field with
patterned or randomized orientation may be applied to a formed
substrate with random particle positions in order to cause greater
diversity of magnetic field orientation.
[0051] The foregoing description illustrates various aspects and
examples of the present disclosure. It is not intended to be
exhaustive. Rather, it is chosen to illustrate the principles of
the present disclosure and its practical application to enable one
of ordinary skill in the art to utilize the present disclosure,
including its various modifications that naturally follow. All
modifications and variations are contemplated within the scope of
the present disclosure as determined by the appended claims.
Relatively apparent modifications include combining one or more
features of various embodiments with features of other
embodiments.
* * * * *