U.S. patent application number 17/606621 was filed with the patent office on 2022-05-19 for cross-certificate method and device for electric vehicle charging.
The applicant listed for this patent is Hyundai Motor Company, Kia Corporation, Myongji University Industry and Academia Cooperation Foundation. Invention is credited to Min Ho Shin.
Application Number | 20220158851 17/606621 |
Document ID | / |
Family ID | 1000006182331 |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220158851 |
Kind Code |
A1 |
Shin; Min Ho |
May 19, 2022 |
CROSS-CERTIFICATE METHOD AND DEVICE FOR ELECTRIC VEHICLE
CHARGING
Abstract
A cross-certificate method is performed by an electric vehicle
(EV) for being supplied with power from electric vehicle supply
equipment (EVSE) associated with a charging point operator (CPO)
having established a trust relationship with a first vehicle to
grid (V2G) root certificate authority (rootCA) and a second V2G
root certificate authority. The cross-certificate method may
include steps of: requesting charging from the electric vehicle
supply equipment; receiving, from the electric vehicle supply
equipment, a certificate chain held by the electric vehicle supply
equipment; and verifying whether or not a last certificate of the
certificate chain has been signed by the second V2G root
certificate authority, wherein the last certificate of the
certificate chain can be a cross-certificate issued by the second
V2G root certificate authority.
Inventors: |
Shin; Min Ho; (Yongin,
Gyeonggi-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company
Kia Corporation
Myongji University Industry and Academia Cooperation
Foundation |
Seoul
Seoul
Yongin, Gyeonggi-do |
|
KR
KR
KR |
|
|
Family ID: |
1000006182331 |
Appl. No.: |
17/606621 |
Filed: |
April 29, 2020 |
PCT Filed: |
April 29, 2020 |
PCT NO: |
PCT/KR2020/005641 |
371 Date: |
October 26, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62933018 |
Nov 8, 2019 |
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62927887 |
Oct 30, 2019 |
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62839996 |
Apr 29, 2019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60L 53/66 20190201;
H04L 9/0825 20130101; H04L 9/3265 20130101; B60L 55/00
20190201 |
International
Class: |
H04L 9/32 20060101
H04L009/32; H04L 9/08 20060101 H04L009/08; B60L 53/66 20060101
B60L053/66; B60L 55/00 20060101 B60L055/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2020 |
KR |
10-2020-0051201 |
Claims
1. A cross certification method performed by an electric vehicle
(EV) for being supplied with electric power from an electric
vehicle supply equipment (EVSE) associated with a charge point
operator (CPO) having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA) and a second
V2G root CA, the cross certification method comprising: requesting
charging from the EVSE; receiving, from the EVSE, a certificate
chain maintained by the EVSE; and verifying that a last certificate
in the certificate chain has been signed by the second V2G root
CA.
2. The cross certification method of claim 1, wherein the last
certificate in the certificate chain is a cross certificate issued
by the second V2G root CA.
3. The cross certification method of claim 2, wherein a public key
in the cross certificate coincides with a public key corresponding
to a private key used to issue the last certificate excluding the
cross certificate in the certificate chain.
4. The cross certification method of claim 2, wherein the last
certificate excluding the cross certificate in the certificate
chain was issued by the first V2G root CA or the CPO.
5. The cross certification method of claim 2, wherein the second
V2G root CA directly issues the cross certificate for the first V2G
root CA by itself.
6. The cross certification method of claim 2, wherein the second
V2G root CA issues the cross certificate for the first V2G root CA
via a cross certification intermediating device.
7. The cross certification method of claim 2, wherein an expiration
date of the cross certificate is set before expiration dates of a
first V2G root certificate and a second V2G root certificate
whichever is earlier.
8. The cross certification method of claim 2, wherein a public key
and an identification (ID) in a certificate issued by the first V2G
root CA are signed by using a private key corresponding to the
cross certificate.
9. The cross certification method of claim 2, wherein a public key
and an identification (ID) in a CPO subordinate CA certificate are
signed by using a private key corresponding to the cross
certificate.
10. A power transfer method performed by an electric vehicle supply
equipment (EVSE) associated with a charge point operator (CPO)
having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA), the power
transfer method comprising: receiving a charging request from an
electric vehicle (EV) trusting a second V2G root CA; providing a
certificate chain maintained by the EVSE to the EV in response to
the charging request; receiving a verification result for the
certificate chain from the EV; and supplying electric power to the
EV depending on the verification result.
11. The power transfer method of claim 10, wherein a last
certificate in the certificate chain is a cross certificate issued
by the second V2G root CA.
12. The power transfer method of claim 10, wherein a last
certificate in the certificate chain is signed by the second V2G
root CA.
13. The power transfer method of claim 11, wherein a public key in
the cross certificate coincides with a public key corresponding to
a private key used to issue the last certificate excluding the
cross certificate in the certificate chain.
14. The power transfer method of claim 11, wherein the last
certificate excluding the cross certificate in the certificate
chain was issued by the first V2G root CA or the CPO.
15. The power transfer method of claim 11, wherein the second V2G
root CA directly issues the cross certificate for the first V2G
root CA by itself.
16. The power transfer method of claim 11, wherein the second V2G
root CA issues the cross certificate for the first V2G root CA via
a cross certification intermediating device.
17. The power transfer method of claim 10, wherein the certificate
chain is sent to the EV in a ServerHello message during a transport
layer security (TLS) handshake operation.
18. The power transfer method of claim 11, wherein a public key and
an identification (ID) in a certificate issued by the first V2G
root CA are signed by using a private key corresponding to the
cross certificate.
19. The power transfer method of claim 11, wherein a public key and
an identification (ID) in a CPO subordinate CA certificate are
signed by using a private key corresponding to the cross
certificate.
20. A cross certification apparatus of an electric vehicle (EV) for
being supplied with electric power from an electric vehicle supply
equipment (EVSE) associated with a charge point operator (CPO)
having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA) and trusts a
second V2G root CA, comprising: a processor; and a memory storing
at least one instruction to be executed by the processor, wherein
the at least one instruction, when executed by the processor,
causes the processor to: request charging from the EVSE; receive,
from the EVSE, a certificate chain maintained by the EVSE; and
verify that a last certificate in the certificate chain has been
signed by the second V2G root CA.
21. The cross certification apparatus of claim 20, wherein the last
certificate in the certificate chain is a cross certificate issued
by the second V2G root CA.
22. The cross certification apparatus of claim 21, wherein a public
key in the cross certificate coincides with a public key
corresponding to a private key used to issue a last certificate
excluding the cross certificate in the certificate chain.
23. The cross certification apparatus of claim 21, wherein the last
certificate excluding the cross certificate in the certificate
chain was issued by the first V2G root CA or the CPO.
24. The cross certification apparatus of claim 21, wherein the
second V2G root CA directly issues the cross certificate for the
first V2G root CA by itself.
25. The cross certification apparatus of claim 21, wherein the
second V2G root CA issues the cross certificate for the first V2G
root CA via a cross certification intermediating device.
Description
BACKGROUND
(a) Technical Field
[0001] The present disclosure relates to a cross certification
method and apparatus, more particularly, to the cross certification
method and apparatus for use in an electric vehicle charging and a
power transfer method using cross certification.
(b) Description of the Related Art
[0002] An electric vehicle (EV) is driven by an electric motor by
power stored in a battery, and produces less pollution such as
exhaust gas and noise compared with a conventional gasoline engine
vehicle, fewer faults, a longer life span, and advantageously,
operation of the EV is simplified.
[0003] Typically EVs are classified into hybrid electric vehicles
(HEVs), plug-in hybrid electric vehicles (PHEVs), and electric
vehicles (EVs), based on a driving source. The HEV has an engine as
a main power source and a motor as an auxiliary power source. The
PHEV has a main power motor and an engine used when a battery is
discharged. The EV has a motor, but the EV does not have an
engine.
[0004] An electric vehicle charging system may be defined as a
system that charges a battery mounted in an electric vehicle using
power obtained from a commercial power grid or stored in an energy
storage device. Such an electric vehicle charging system may have
various forms depending on a type of the electric vehicle. For
example, the electric vehicle charging system may include a
conductive charging system using a cable or a non-contact wireless
power transfer system.
[0005] In this regard, an eMobility service is a business segment
that provides a service of supplying electricity to an EV user who
owns or drives the EV or an organization that owns and operates the
EVs for their own business such as transportations, logistics, or
rental services. A typical eMobility service provider executes a
contract with the EV user including the organizations mentioned
above and bills for the electricity based on the amount of the
electricity used for the charging or the other billing criteria.
From a business point of view, it is important to authenticate the
EV user when the EV is charged because revenue of the eMobility
service provider will be at risk if there is no adequate manner of
authenticating the EV user. Further, the entire charging
infrastructure and the power grid located behind the charging
infrastructure are vulnerable to malicious attempts by an
unauthorized group exploiting the security vulnerabilities for a
political or financial motive or for a sense of fulfillment.
SUMMARY
[0006] To solve the problems above, provided is a cross
certification method performed by an electric vehicle.
[0007] Provided is a power transfer method performed by a charge
point operator.
[0008] Provided is a cross certification apparatus for an electric
vehicle using the cross certification method.
[0009] According to an aspect of an exemplary embodiment, provided
is a cross certification method performed by an electric vehicle
(EV) for being supplied with electric power from an electric
vehicle supply equipment (EVSE) associated with a charge point
operator (CPO) having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA) and trusts a
second V2G root CA. The cross certification method includes:
requesting charging from the EVSE; receiving, from the EVSE, a
certificate chain maintained by the EVSE; and verifying that a last
certificate in the certificate chain has been signed by the second
V2G root CA.
[0010] The last certificate in the certificate chain may be a cross
certificate issued by the second V2G root CA.
[0011] A public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue a last
certificate excluding the cross certificate in the certificate
chain.
[0012] The last certificate excluding the cross certificate in the
certificate chain may have been issued by the first V2G root CA or
the CPO.
[0013] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself.
[0014] The second V2G root CA may issue the cross certificate for
the first V2G root CA via a cross certification intermediating
device.
[0015] The expiration date of the cross certificate may be set
before expiration dates of a first V2G root certificate and a
second V2G root certificate whichever is earlier.
[0016] A public key and an identification (ID) in a certificate
issued by the first V2G root CA may be signed by using a private
key corresponding to the cross certificate.
[0017] A public key and an identification (ID) in a CPO subordinate
CA certificate may be signed by using a private key corresponding
to the cross certificate.
[0018] According to another aspect of an exemplary embodiment,
provided is a power transfer method performed by an electric
vehicle supply equipment (EVSE) associated with a charge point
operator (CPO) having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA). The power
transfer method includes: receiving a charging request from an
electric vehicle (EV) trusting a second V2G root CA; providing a
certificate chain maintained by the EVSE to the EV in response to
the charging request; receiving a verification result for the
certificate chain from the EV; and supplying electric power to the
EV depending on the verification result.
[0019] A last certificate in the certificate chain may be a cross
certificate issued by the second V2G root CA.
[0020] A public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue a last
certificate excluding the cross certificate in the certificate
chain.
[0021] The last certificate excluding the cross certificate in the
certificate chain may have been issued by the first V2G root CA or
the CPO.
[0022] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself.
[0023] The second V2G root CA may issue the cross certificate for
the first V2G root CA via a cross certification intermediating
device.
[0024] The certificate chain may be sent to the EV in a ServerHello
message during a transport layer security (TLS) handshake
operation.
[0025] A public key and an identification (ID) in a certificate
issued by the first V2G root CA may be signed by using a private
key corresponding to the cross certificate.
[0026] A public key and an identification (ID) in a CPO subordinate
CA certificate may been signed by using a private key corresponding
to the cross certificate.
[0027] According to yet another aspect of an exemplary embodiment,
provided is a cross certification apparatus of an electric vehicle
(EV) for being supplied with electric power from an electric
vehicle supply equipment (EVSE) associated with a charge point
operator (CPO) having established a trust relationship with a first
vehicle-to-grid (V2G) root certificate authority (CA) and trusts a
second V2G root CA. The cross certification apparatus includes: a
processor; and a memory storing at least one instruction to be
executed by the processor. The at least one instruction, when
executed by the processor, causes the processor to: request
charging from the EVSE; receive, from the EVSE, a certificate chain
maintained by the EVSE; and verify that a last certificate in the
certificate chain has been signed by the second V2G root CA.
[0028] The last certificate in the certificate chain may be a cross
certificate issued by the second V2G root CA.
[0029] A public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue a last
certificate excluding the cross certificate in the certificate
chain.
[0030] The last certificate excluding the cross certificate in the
certificate chain may have been issued by the first V2G root CA or
the CPO.
[0031] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself.
[0032] The second V2G root CA may issue the cross certificate for
the first V2G root CA via a cross certification intermediating
device.
[0033] The cross certification method of the present disclosure
enables to manage the trusts flexibly in the EV charging network or
system.
BRIEF DESCRIPTION OF DRAWINGS
[0034] FIG. 1 is a conceptual diagram illustrating an EV conductive
charging system to which an exemplary embodiment of the present
disclosure may be applied;
[0035] FIG. 2 is a conceptual diagram illustrating a wireless power
transfer (WPT) system to which an exemplary embodiment of the
present disclosure may be applied;
[0036] FIG. 3 illustrates an overview of a certificate structure in
an electric vehicle charging system to which the present disclosure
may be applied;
[0037] FIGS. 4A and 4B illustrate a concept of a cross
certification between V2G root certification authorities (CAs)
according to an exemplary embodiment of the present disclosure;
[0038] FIG. 5 illustrates a concept of a cross certification
between a V2G root CA and an OEM root CA according to another
exemplary embodiment of the present disclosure;
[0039] FIG. 6 illustrates a cross certification method between the
V2G root CAs according to an exemplary embodiment of the present
disclosure;
[0040] FIG. 7 illustrates a certificate verification procedure in a
system adopting the cross certification between the V2G operators
according to an exemplary embodiment of the present disclosure;
[0041] FIGS. 8A and 8B show the cross certification method between
the V2G operators according to another embodiment of the present
disclosure;
[0042] FIGS. 9A and 9B illustrate a concept of a cross
certification using a bridge CA according to another embodiment of
the present disclosure;
[0043] FIG. 10 is a flowchart showing the cross certification
method for EV charging according to an exemplary embodiment of the
present disclosure;
[0044] FIG. 11 is a flowchart showing a power transfer method
according to an exemplary embodiment of the present disclosure;
and
[0045] FIG. 12 is a block diagram of a cross certification
apparatus according to an exemplary embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0046] For a more clear understanding of the features and
advantages of the present disclosure, exemplary embodiments of the
present disclosure will be described in detail with reference to
the accompanied drawings. However, it should be understood that the
present disclosure is not limited to particular embodiments and
includes all modifications, equivalents, and alternatives falling
within the idea and scope of the present disclosure. In describing
each drawing, similar reference numerals have been used for similar
components.
[0047] The terminologies including ordinals such as "first" and
"second" designated for explaining various components in this
specification are used to discriminate a component from the other
ones but are not intended to be limiting to a specific component.
For example, a second component may be referred to as a first
component and, similarly, a first component may also be referred to
as a second component without departing from the scope of the
present disclosure.
[0048] When a component is referred to as being "connected" or
"coupled" to another component, the component may be directly
connected or coupled logically or physically to the other component
or indirectly through an object therebetween. In contrast, when a
component is referred to as being "directly connected" or "directly
coupled" to another component, it is to be understood that there is
no intervening object between the components.
[0049] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a," "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0050] Unless defined otherwise, all terms used herein, including
technical or scientific terms, have the same meaning as commonly
understood by those of ordinary skill in the art to which the
present disclosure pertains. Terms such as those defined in a
commonly used dictionary should be interpreted as having meanings
consistent with meanings in the context of related technologies and
should not be interpreted as having ideal or excessively formal
meanings unless explicitly defined in the present application.
[0051] Terms used in the present disclosure are defined as
follows.
[0052] "Electric Vehicle (EV)": An automobile, as defined in 49 CFR
523.3, intended for highway use, powered by an electric motor that
draws current from an on-vehicle energy storage device, such as a
battery, which is rechargeable from an off-vehicle source, such as
residential or public electric service or an on-vehicle fuel
powered generator. The EV may be a four or more wheeled vehicle
manufactured for use primarily on public streets or roads.
[0053] The EV may include an electric vehicle, an electric
automobile, an electric road vehicle (ERV), a plug-in vehicle (PV),
a plug-in vehicle (xEV), etc., and the xEV may be classified into a
plug-in all-electric vehicle (BEV), a battery electric vehicle, a
plug-in electric vehicle (PEV), a hybrid electric vehicle (HEV), a
hybrid plug-in electric vehicle (HPEV), a plug-in hybrid electric
vehicle (PHEV), etc.
[0054] "Plug-in Electric Vehicle (PEV)": An Electric Vehicle that
recharges the on-vehicle primary battery by connecting to the power
grid.
[0055] "Plug-in Vehicle (PV)": An electric vehicle rechargeable
through wireless charging from an electric vehicle supply equipment
(EVSE) without using a physical plug or a physical socket.
[0056] "Heavy duty vehicle (H.D. Vehicle)": Any four-or more
wheeled vehicle defined in 49 CFR 523.6 or 49 CFR 37.3 (bus).
[0057] "Light duty plug-in electric vehicle": A three or
four-wheeled vehicle propelled by an electric motor drawing current
from a rechargeable storage battery or other energy devices for use
primarily on public streets, roads, and highways and rated at less
than 4,545 kg gross vehicle weight.
[0058] "Wireless power charging system (WCS)": A system for
wireless power transfer and control of interactions including
operations for an alignment and communications between a ground
assembly (GA) and a vehicle assembly (VA).
[0059] "Wireless power transfer (WPT)": A transfer of electric
power between a power source such as a utility, the power grid, an
energy storage device, a fuel cell generator and the EV through a
contactless channel such as electromagnetic induction and
resonance.
[0060] "Utility": A set of systems which supply electrical energy
and include a customer information system (CIS), an advanced
metering infrastructure (AMI), rates and revenue system, etc. The
utility may provide an EV with energy through rates table and
discrete events. Also, the utility may provide information related
to certification on EVs, interval of power consumption
measurements, and tariff.
[0061] "Smart charging": A system in which EVSE and/or PEV
communicate with power grid to optimize charging ratio or
discharging ratio of EV by reflecting capacity of the power grid or
expense of use.
[0062] "Automatic charging": A procedure in which inductive
charging is automatically performed after a vehicle is located in a
proper position corresponding to a primary charger assembly capable
of transferring power. The automatic charging may be performed
after obtaining necessary authentication and access.
[0063] "Interoperability": A state in which components of a system
interwork with corresponding components of the system to perform
operations aimed by the system. Additionally, information
interoperability may refer to capability that two or more networks,
systems, devices, applications, or components may efficiently share
and easily use information without causing inconvenience to
users.
[0064] "Inductive charging system": A system transferring energy
from a power source to an EV via a two-part gapped core transformer
in which the two halves of the transformer, i.e., primary and
secondary coils, are physically separated from one another. In the
present disclosure, the inductive charging system may correspond to
an EV power transfer system.
[0065] "Inductive coupler": A transformer formed by the coil in a
ground assembly (GA) coil and the coil in a vehicle assembly (VA)
coil that allows power to be transferred with galvanic
isolation.
[0066] "Inductive coupling": A magnetic coupling between two coils.
One of the two coils may refer to the ground assembly (GA) coil,
and the other one of the two coils may refer to the vehicle
assembly (VA) coil.
[0067] "Ground assembly (GA)": An assembly on the ground or
infrastructure side including the GA coil, a power/frequency
conversion unit, and GA controller as well as the wiring from the
grid and between each unit, filtering circuits, housing(s) etc.,
necessary to function as the power source of wireless power
charging system. The GA may include components suitable for
controlling impedances and resonant frequencies including ferrites
and electromagnetic shielding materials for enhancing magnetic flus
paths.
[0068] "Vehicle assembly (VA)": An assembly within the vehicle
including the VA coil, rectifier/power conversion unit and VA
controller as well as the wiring to the vehicle batteries and
between each unit, filtering circuits, housing(s), etc., necessary
to function as the vehicle part of a wireless power charging
system. The VA may include components suitable for controlling
impedances and resonant frequencies including ferrites and
electromagnetic shielding materials for enhancing magnetic flus
paths.
[0069] The GA may be referred to as a supply device, a primary
device, and so on, and the VA may be referred to as an EV device, a
secondary device, and so on.
[0070] "Primary device": An apparatus which provides a contactless
coupling to the secondary device. In other words, the primary
device may be an apparatus extraneous to an EV. When the EV is
receiving power, the primary device may act as a source of the
transferred power. The primary device may include the housing and
all covers.
[0071] "Secondary device": An apparatus mounted within the EV which
provides the contactless coupling to the primary device. In other
words, the secondary device may be installed within the EV. When
the EV is receiving power, the secondary device may transfer the
power from the primary to the EV. The secondary device may include
the housing and all covers.
[0072] "GA controller": A portion of the GA which regulates the
output power level to the GA coil based on information from the
vehicle.
[0073] "VA controller": A portion of the VA which monitors certain
in-vehicle parameters during charging and initiates communication
with the GA to adjust an output power level.
[0074] The GA controller may be referred to as a primary device
communication controller (PDCC), and the VA controller may be
referred to as an electric vehicle communication controller
(EVCC).
[0075] "Magnetic gap": A vertical distance between the plane of the
higher of the top of the litz wire or the top of the magnetic
material in the GA coil to the plane of the lower of the bottom of
the litz wire or the magnetic material in the VA coil when
aligned.
[0076] "Ambient temperature": A ground-level temperature of the air
measured at the subsystem under consideration and not in direct sun
light.
[0077] "Vehicle ground clearance": A vertical distance between the
ground surface and the lowest part of the vehicle floor pan.
[0078] "Vehicle magnetic ground clearance": A vertical distance
between the plane of the lower of the bottom of the litz wire or
the magnetic material in the VA Coil mounted within a vehicle to
the ground surface.
[0079] "VA Coil magnetic surface distance": A distance between the
plane of the nearest magnetic or conducting component surface to
the lower exterior surface of the VA coil when mounted. This
distance includes any protective coverings and additional items
that may be packaged in the VA Coil enclosure.
[0080] The VA coil may be referred to as a secondary coil, a
vehicle coil, or a receive coil. Similarly, the GA coil may be
referred to as a primary coil, or a transmit coil.
[0081] "Exposed conductive component": A conductive component of
electrical equipment (e.g. an electric vehicle) that may be touched
and which is not normally energized but which may become energized
in case of a fault.
[0082] "Hazardous live component": A live component, which under
certain conditions may output a harmful electric shock.
[0083] "Live component": Any conductor or conductive component
intended to be electrically energized in normal use.
[0084] "Direct contact": A contact of persons with live components.
(See IEC 61440)
[0085] "Indirect contact": A contact of persons with exposed,
conductive, and energized components made live by an insulation
failure. (See IEC 61140)
[0086] "Alignment": A process of detecting a relative position of
primary device to secondary device and/or detecting the relative
position of secondary device to primary device for the efficient
power transfer that is specified. In the present disclosure, the
alignment may direct to a fine positioning of the wireless power
transfer system.
[0087] "Pairing": A process by which a vehicle is correlated with
the unique dedicated primary device, at which it is located and
from which the power will be transferred. Pairing may include the
process by which a VA controller and a GA controller of a charging
spot are correlated. The correlation/association process may
include the process of establishing a relationship between two peer
communication entities.
[0088] "High level communication (HLC)": A particular type of
digital communication. The HLC is necessary for additional services
which are not covered by command & control communication. The
data link of the HLC may use a power line communication (PLC), but
it is not limited.
[0089] "Low power excitation (LPE)": A technique of activating the
primary device for the fine positioning and pairing to allow the EV
to detect the primary device, and vice versa.
[0090] "Service set identifier (SSID)": A unique identifier
consisting of 32-characters attached to a header of a packet
transmitted on a wireless LAN. The SSID identifies the basic
service set (BSS) to which the wireless device attempts to connect.
The SSID distinguishes multiple wireless LANs. Therefore, all
access points (APs) and all terminal/station devices that want to
use a specific wireless LAN may use the same SSID. Devices that do
not use a unique SSID are not able to join the BSS. Since the SSID
is shown as plain text, it may not provide any security features to
the network.
[0091] "Extended service set identifier (ESSID)": A name of a
network to which one desires to connect. It is similar to SSID but
may be a more extended concept.
[0092] "Basic service set identifier (BSSID)": The BSSID typically
consists of 48 bits and is used to distinguish a specific BSS. In
the case of an infrastructure BSS network, the BSSID may be a
medium access control (MAC) of the AP equipment. For an independent
BSS or ad hoc network, the BSSID may be generated with any
value.
[0093] A charging station may include at least one GA and at least
one GA controller configured to manage the at least one GA. The GA
may include at least one wireless communication device. The
charging station may refer to a location having at least one GA,
which is installed in home, office, public place, road, parking
area, etc.
[0094] Hereinbelow, exemplary embodiments of the present disclosure
will be described in detail with reference to the accompanying
drawings.
[0095] FIG. 1 is a conceptual diagram illustrating an EV conductive
charging system to which an exemplary embodiment of the present
disclosure may be applied.
[0096] As shown in FIG. 1, the EV conductive charging may be
performed based on an interworking of an EV charging cable 30, an
EV 10, and a power outlet 40 installed in an existing building or
charging stand.
[0097] The EV 10 may be generally defined as an automobile that
supplies an electric current from a rechargeable energy storage
device such as a battery mounted on the EV 10 as an energy source
of an electric motor.
[0098] The EV 10 may be a hybrid electric vehicle (HEV) having an
electric motor as well as an internal combustion engine. Also, the
EV 10 may be not only an automobile but also a motorcycle, a cart,
a scooter, or an electric bicycle.
[0099] Further, the EV 10 according to the present disclosure may
include an inlet for the conductive charging of its battery. Here,
the EV 10 of which battery may be conductively charged may be
referred to as a plug-in electric vehicle (PEV) as defined
above.
[0100] The inlet provided in the EV 10 according to the present
disclosure may support a slow charging or a rapid charging. Here,
the EV 10 may include either a single inlet that supports both of
the slow charging and the rapid charging through a single plug
connection, or inlets that respectively support the slow charging
and the rapid charging.
[0101] In addition, the EV 10 according to the present disclosure
may further include an on-board charger (OBC) to support the slow
charging by an alternating current (AC) power supplied from a
general power system. The OBC may boost a level of the AC power
supplied from the general power system and convert into a direct
current (DC) power to supply the DC power to the battery of the EV
10 during the course of the slow charging. Accordingly, in case the
AC power for the slow charging is supplied to the inlet of the EV
10, the slow charging may be performed through the OBC. In
contrast, in case the DC power for the rapid charging is supplied
to the inlet of the EV 10, the rapid charging may be performed
without an intervention of the OBC.
[0102] The EV charging cable 30 may include at least one of a
charging plug 31 connected to the inlet of the EV 10, an outlet
plug 33 connected to the outlet 40, or an in-cable control box
(ICCB) 32.
[0103] The charging plug 11 may be a connection part that can be
electrically connected to the inlet of the EV 10. The ICCB 12 may
communicate with the EV 10 to receive status information of the EV
or to control the electric power charging of the EV 10.
[0104] Although the ICCB 12 is illustrated as being included in the
EV charging cable 10, the ICCB 12 may be mounted in a place other
than the EV charging cable 10 or may be combined with an SECC
described below or replaced by the SECC.
[0105] The outlet plug 13, which is suitable for being connected to
the outlet of the charging stand to receive the power, may be an
electrical connection member such as a general plug or a cord
set.
[0106] The electric power outlet 30 may refer to an outlet
installed at various places such as a parking lot attached to a
house of an owner of the EV 10, a parking area for charging an EV
at a gas station, or a parking area at a shopping center or an
office building, for example.
[0107] In addition, a device referred to as a supply equipment
communications controller (SECC) may be installed in a building or
place (e.g., a charging stand) where the outlet 30 is installed to
control a charging procedure by communicating with one of the
components of the ICCB 12 or the EV 10 (e.g., electric vehicle
communications controller (EVCC)).
[0108] The SECC may communicate with a power grid, an
infrastructure management system that manages the power grid, a
management server (hereinbelow, referred to as `server`) of the
building in which the outlet 30 is installed, or an infrastructure
server through wired or wireless communications.
[0109] The power outlet 40 may supply the AC power of the power
system as it is. For example, the power outlet 40 may supply the AC
power corresponding to at least one of single-phase two-wire (1P2W)
system or a three-phase four-wire (3P4W) system.
[0110] The EV charging cable 30 may support the slow charging and
supply the electric power for the slow charging to the EV 10. The
electric power supplied to the EV 10 for the slow charging may be
in a range of 3.3 to 7.7 kWh.
[0111] The EV charging cable 30 may support the rapid charging and
supply the electric power for the rapid charging to the EV 10. The
electric power supplied to the EV 10 for the rapid charging may be
in a range of 50 to 100 kWh.
[0112] FIG. 2 is a conceptual diagram illustrating a concept of a
wireless power transfer (WPT) to which an exemplary embodiment of
the present disclosure may be applied.
[0113] As shown in FIG. 2, a WPT may be performed by at least one
component of an electric vehicle (EV) 10 and a charging station 20
and may be used for transferring power to the EV 10 without any
wire.
[0114] Particularly, the EV 10 may be usually defined as a vehicle
that supplies an electric power stored in the rechargeable energy
storage including a battery 12 to an electric motor in a power
train system of the EV 10.
[0115] The EV 10 according to an exemplary embodiment of the
present disclosure may include a hybrid electric vehicle (HEV)
having an electric motor as well as an internal combustion engine,
and may include not only an automobile but also a motorcycle, a
cart, a scooter, and an electric bicycle.
[0116] The EV 10 may include a power reception pad 11 that has a
reception coil suitable for receiving the electric power for
charging the battery 12 wirelessly or and may include a plug
receptacle suitable for receiving the electric power for
conductively charging the battery 12. In particular, the EV 10
configured for conductively charging the battery 12 may be referred
to as a plug-in electric vehicle (PEV).
[0117] The charging station 20 may be connected to the power grid
50 or a power backbone, and may provide the AC power to a power
transmission pad 21 having a transmission coil via a power
link.
[0118] The charging station 20 may communicate with the power grid
50, or the infrastructure management system or an infrastructure
server that manages the power grid, and may be configured to
perform wireless communications with the EV 10.
[0119] The wireless communications may be performed through
Bluetooth, Zigbee, cellular, wireless local area network (WLAN), or
the like.
[0120] Additionally, the charging station 20 may be located at
various places including a parking area attached to the owner's
house of the EV 10, a parking area for charging an EV at a gas
station or the like, a parking area at a shopping center or a
workplace, but is not limited thereto.
[0121] The wireless power transfer to the battery 12 of the EV 10
may be performed as follows. First, the power reception pad 11 of
the EV 10 is disposed in an energy field generated by the power
transmission pad 21. Then the reception coil in the power reception
pad 21 and the transmission coil in the power transmission pad 11
are coupled to and interacts each other. An electromotive force may
be induced in the power reception pad 11 as a result of the
coupling or the interaction, and the battery 12 may be charged by
the induced electromotive force.
[0122] The charging station 20 and the power transmission pad 21 as
a whole or in part may be referred to as the ground assembly (GA),
of which meaning and function were defined above.
[0123] Also, all or part of the power reception pad 11 and other
internal components of the EV 10 may be referred to as the vehicle
assembly (VA), of which meaning and function were defined
above.
[0124] The power transmission pad or the power reception pad may be
configured to be non-polarized or polarized.
[0125] In case the pad is non-polarized, there is one pole in a
center of the pad and an opposite pole around an external periphery
of the pad. The magnetic flux may be formed to exit from the center
of the pad and return to external boundaries of the pad.
[0126] In case the pad is polarized, the pad may have respective
poles at opposite end portions of the pad. The magnetic flux may be
formed based according to an orientation of the pad.
[0127] Meanwhile, according to ISO 15118 which is a communication
standard document for the electric vehicle charging, the EV and an
electric vehicle supply equipment (EVSE) control the entire
charging process by exchanging messages. In detail, the electric
vehicle communications controller (EVCC) and the supply equipment
communications controller (SECC) performs the communication for the
electric vehicle charging.
[0128] After the EV verifies the identity of the EVSE to ensure
that the EVSE is a trusted facility approved by a trusted operator,
the EV establishes a secure channel with the EVSE to protect
communications from an unauthorized access. Such a communication
security may be secured by Transport Layer Security (TLS) which is
a standardized protocol defined in Request for Comments (RFC) 5246,
Internet Engineering Task Force (IETF). A TLS session may be
established by a TLS session establishment procedure after an
establishment of an IP-based communication connection. The security
of the TLS relies on an assumption of trust of the EV for a trusted
operator to which the EVSE belongs.
[0129] FIG. 3 illustrates an overview of a certificate structure in
a charging system to which the present disclosure may be
applied.
[0130] FIG. 3 visually depicts the certificate structure according
to the ISO 15118 standard.
[0131] As shown in FIG. 3, an original equipment manufacturer (OEM)
provisioning certificate is independent from public key
infrastructure (PKI) sets of secondary actors which is under a
global root certificate. A root certificate (OEM root CA cert) for
the OEM provisioning certificate may be generated by an OEM itself.
However, it is also possible to reuse a vehicle-to-grid (V2G) root
certificate (V2G root CA cert) as a mobility operator root
certificate (MO root CA cert) or the OEM root certificate (OEM root
CA cert), as indicated by dashed lines.
[0132] According to the ISO 15118 standard, the V2G operator may
issue a digital certificate to entities related with an EV charging
infrastructure. In particular, the V2G operator may set a V2G root
certification authority (V2G root CA) to issue the self-signed root
certificate (V2G Root CA cert) 500, and issue an intermediate
certificate (V2G Sub-CA cert) 510 to a V2G subordinate
certification authority (V2G Sub-CA). The V2G subordinate
certification authority (V2G Sub-CA) may issue certificates for the
EVSE or other subordinate certification authorities (V2G
Sub-CAs).
[0133] Referring to FIG. 3, there may be up to two intermediate
certificates (V2G Sub-CA certs) between the V2G root certificate
(V2G Root CA Cert) and an EVSE leaf certificate. The certificates
from the EVSE leaf certificate to a last intermediate certificate
(CPO Sub-CA1 cert) issued by the V2G root CA may be referred to as
a certificate chain for the EVSE. The certificate chain for the
EVSE may include two certificates (EVSE leaf cert and CPO Sub-CA1
cert) or 3 certificates (EVSE leaf cert, CPO Sub-CA2 cert, and CPO
Sub-CA1 cert). The certificates may be issued along the certificate
chain, and the highest certificate in the chain may be the root
certificate issued by the V2G root CA.
[0134] To prove its identity, the EVSE may send its certificate
chain to the EV during a TLS handshaking process. Then, the EV
validates the EVSE leaf certificate by verifying the signature of
each certificate in the chain using the public keys included in the
certificates in the chain. If the EV is not equipped with the V2G
root certificate issued by the V2G root CA in advance, the EV
cannot verify the signature of the last certificate in the chain.
Therefore, the EV may have to maintain a series of V2G root
certificates issued by the trusted V2G operators as trust
anchors.
[0135] The EV may store only a limited number of V2G root
certificates in a consideration of a burden of EV memory check.
Further, once the EV is sold out to an EV user, it is difficult to
update the trust anchors. Accordingly, a situation may arises in
which the EV user cannot charge the EV at an EVSE which has a
certificate issued by at least one trusted V2G operator. In
particular, such a situation may cause an inconvenience to the EV
user when the EV moved into an area where there is no EV charging
infrastructure certified by the trusted V2G operator. The only
solution to this problem available currently is to bring the EV to
a factory and install a new set of trust anchors or replace the set
of trust anchors which the EV user needs in the new area. However,
this method incurs a very high cost and is inconvenient and
unreliable.
[0136] The present disclosure provides a cross certification method
to solve the problem.
[0137] Method of implementing the cross certification according to
the present disclosure may include a cross certification between
two V2G CAs, a cross certification between a V2G CA and an OEM CA,
and a cross certification using a separate cross certification
broker, e.g. a bridge-CA.
[0138] FIGS. 4A and 4B illustrate a concept of the cross
certification between the V2G root CAs according to an exemplary
embodiment of the present disclosure.
[0139] As shown in FIG. 4A, if there is a cross certificate
contract concluded between V2G operators, an EV trusting a certain
V2G root CA may receive a charging service from an EVSE having a
certificate issued by a subordinate CA of another V2G root CA.
Also, as shown in FIG. 4B, an EV trusting a certain V2G root CA may
verify a certificate signed by a certificate provisioning service
(CPS) of another V2G root CA. That is, the EV may validate the
certificate issued by a subordinate CA of another V2G root CA.
[0140] FIG. 5 illustrates a concept of the cross certification
between the V2G root CA and the OEM root CA according to another
exemplary embodiment of the present disclosure.
[0141] Referring to FIG. 5, a charge point operator (CPO) or the
CPS may verify an OEM certificate without the OEM root certificate
when the cross certification between the V2G root CA and the OEM
root CA is used.
[0142] The cross certification according to the present disclosure
enables the EV to validate the EVSE certificate chain even when the
EVSE certificate chain is not issued by the V2G CAs trusted by the
EV. In other words, even if the EVSE certificate chain ends with an
intermediate certificate issued based on a V2G root certificate
which is not maintained by the EV, the EVSE may prove that the
certificate chain has been cross certified by one of the V2G
operators trusted by the EV, and the EV may validate the
certificate chain.
[0143] This is possible because, according to a validation process
defined in the RFC 5280, the verification may be successful as long
as a certificate chain leads to a trusted V2G root certificate
along a signature validation path.
[0144] FIG. 6 illustrates the cross certification method between
the V2G root CAs according to an exemplary embodiment of the
present disclosure.
[0145] In the embodiment of FIG. 6, it is assumed that a SECC
certificate chain includes the SECC leaf certificate (i.e. EVSE
leaf certificate), a second intermediate certificate (Sub-CA 2
cert), and a first intermediate certificate (Sub-CA 1 cert), and
the first intermediate certificate (Sub-CA 1 cert) has been signed
by the V2G-A root certificate (denoted by `KRV2G root CA cert` in
FIG. 6).
[0146] Here, the first intermediate certificate (Sub-CA 1 cert) may
be issued to a charge point operator (CPO), and the V2G root
certificate is issued to itself by the V2G root CA. The SECC leaf
certificate and the second intermediate certificate (Sub-CA 2 cert)
are issued by the CPO. The first intermediate certificate (Sub-CA 1
cert) and the KOV2G root certificate are issued by the KOV2G root
CA.
[0147] If the cross certification is not used in the system and the
EV has a V2G-B root certificate (DE V2G root CA cert), the
signature of the issuer of the first intermediate certificate
(Sub-CA 1 cert) cannot be verified using the public key of the
V2G-B root certificate.
[0148] If, however, a V2G-B root CA (DE V2G root CA) issues a cross
certificate (cross cert; x-cert) for the V2G-A root CA (KRV2G root
CA) and the cross certificate is added to an end of the certificate
chain, the EV can trust the chain. More specifically, the EV may
successfully trace and verify the SECC leaf certificate, the second
intermediate certificate (Sub-CA 2 cert), the first intermediate
certificate (Sub-CA 1 cert), the cross certificate (x-cert), and
the V2G-B root certificate in that order to trust the identity of
the EVSE presenting the certificates under the trusted V2G-B root
certificate.
[0149] The EV trusting only the V2G-B PKI set may utilize the
charging infrastructure operated based on the V2G-A PKI set by
using the cross certification as follows.
[0150] First, the V2G-A operator may conclude a contract for the
cross certification with the V2G-B operator. Accordingly, the CPS
of the V2G-B root CA may issue a cross certificate (CrossB2A) by
signing the public key and the identification (ID) of the V2G-A
root CA with a private key of the V2G-B root CA. In this case, the
expiration date of the cross certificate (CrossB2A) may be set
before the expiration dates of the V2G-A root certificate and the
V2G-B root certificate whichever is earlier. The cross certificate
(CrossB2A) generated as above may be distributed to all the EVSEs
under the V2G-A root CA.
[0151] Afterwards, when an EVSE under the V2G-A root CA meets an EV
that trusts only the V2G-B root CA, the EVSE may send the
certificate chain including the cross certificate (CrossB2A) in a
ServerHello message, for example, during a transport layer security
(TLS) handshake operation. Since the public key in the cross
certificate (CrossB2A) is identical to the public key in the V2G-A
root certificate, the EV can successfully verify the signature of
the last intermediate certificate (Sub-CA 1 cert) in the
certificate chain with the cross certificate (CrossB2A). The EV can
successfully complete the validation procedure by verifying that
the cross certificate (CrossB2A) has been signed by the trusted
V2G-B root CA.
[0152] FIG. 7 illustrates a certificate verification procedure in a
system adopting the cross certification between the V2G operators
according to an exemplary embodiment of the present disclosure.
[0153] According to the embodiment shown in FIG. 7, the DE V2G
operator and the KR V2G operator may conclude the cross
certification contract, and the DE V2G root CA may issue the cross
certificate (CrossB2A). The issuer of the cross certificate
(CrossB2A) is "DE . . . DE V2G root CA" and the subject of the
cross certificate is "KR . . . KRV2G root CA". Also, in the
embodiment shown in FIG. 7, the subject "KR . . . KRV2G root CA" of
the cross certificate may be the same as the subject of another
cross certificate (KOV2G root CA cert).
[0154] FIGS. 8A and 8B show the cross certification method between
the V2G operators according to another embodiment of the present
disclosure.
[0155] According to the present embodiment, the cross certificate
may be issued to the subordinate certification authorities (Sub-CA
1 or Sub-CA 2) rather than the root CA. FIG. 8A shows an example in
which the cross certificate is issued to the first subordinate CA
(Sub-CA 1), and FIG. 8B shows an example in which the cross
certificate is issued to the second subordinate CA (Sub-CA 2).
[0156] This method enables to maintain the certificate chain length
shorter. For example, the ISO 15118-2:2014 standard limits the
certificate chain length to three and the ISO 15118-20 standard
which is currently under preparation for establishment may limit
the certificate chain length to four. The cross certification
method of the present embodiment may facilitate to meet the
provisions of these standards by reducing the certificate chain
length by one or two.
[0157] Meanwhile, according to another embodiment of the present
disclosure, the cross certification may be accomplished in multiple
stages. For example, the V2G-A root certificate be cross-certified
by the V2G-B root CA, and the V2G-B root certificate may be
cross-certified by a V2G-C root CA. Such a multi-level cross
certification may provide flexibility and scalability of the
interoperability between the V2G operators. A possible application
of this feature may be the cross certification broker. The cross
certification broker may conclude contracts with a plurality of V2G
operators to cross-certify each other. As a result, the
interoperability between the V2G operators associated with the
cross certification broker by respective contracts may be
enhanced.
[0158] FIGS. 9A and 9B illustrate a concept of a cross
certification using a bridge CA according to another embodiment of
the present disclosure.
[0159] Referring to FIG. 9A, when the cross certifications are
required among four V2G CAs, for example, the cross certifications
may be accomplished through a separate bridge CA instead of
individual cross certifications between all the possible pairs
among the V2G CAs. The bridge CA may enhance the interoperability
between the V2G CAs and the scalability in an environment where
more V2G CAs may be added.
[0160] FIG. 9B shows that a roaming service may be available in a
system where a simple PnC scheme is applied by use of the bridge
CA.
[0161] FIG. 10 is a flowchart showing the cross certification
method for EV charging according to an exemplary embodiment of the
present disclosure.
[0162] The cross certification method shown in FIG. 10 may be
performed by the EV that needs to be supplied with electric power
from the EVSE operated by a charge point operator (CPO) having a
contractual relationship with the first V2G root CA. In this case,
it is assumed that the EV has a trust relationship with the second
V2G root CA. In particular, the operator of the first V2G root CA
may conclude a certification contract with the operator of the
second V2G root CA directly or through an intermediating
device.
[0163] First, the EV that needs charging may request charging from
the charge point operator (S1010). The charge point operator may
include the EVSE. A charging request may include a certificate
installation request (CertificateInstallationReq) message, and an
element `ListOfRootCertIDs` for the root certificate ID list in the
CertificateInstallationReq message may be set to "[(V2G1,
<serial>)]".
[0164] The EV may receive a certificate chain maintained by the
charge point operator from the charge point operator as a response
to the charging request (S1020). The certificate chain may be a CPS
certificate chain and may be included in a certificate installation
response (CertificateInstallationRes) message.
[0165] Upon receiving the certificate chain, the EV may verify
whether the last intermediate certificate in the certificate chain
has been signed by the second V2G root CA (S1030). More
specifically, the EV may check whether the cross certificate was
signed by the second V2G root CA. That is, the last intermediate
certificate in the certificate chain may be the cross certificate
issued by the second V2G root CA.
[0166] The public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue the last
certificate except for the cross certificate in the certificate
chain. The certification authority having issued the last
certificate other than the cross certificate in the certificate
chain may be the first V2G root CA or the CPO.
[0167] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself. Alternatively, the
second V2G root CA may indirectly issue the cross certificate for
the first V2G root CA via another device such as the other V2G root
CA or the intermediating device.
[0168] FIG. 11 is a flowchart showing a power transfer method
according to an exemplary embodiment of the present disclosure.
[0169] The power transfer method shown in FIG. 11 may be performed
by a server operated by the charge point operator (CPO) having a
trust relationship with the first V2G root CA or an individual EVSE
operated by the CPO. However, the subject performing the method is
indicated by the CPO in the following description for the sake of
convenience in the description.
[0170] When the CPO having established a trust relationship with
the first V2G route CA receives a charging request from the EV that
trusts the second V2G route CA (S1110), the CPO may provide the
certificate chain maintained therein to the EV (S1120). At this
time, the CPO may send the certificate chain by including the
certificate chain in the ServerHello message during the TLS
handshake operation.
[0171] After the EV completes the verification of the certificate
chain, the CPO may receive a verification result for the
certificate chain from the EV (S1130).
[0172] Finally, the CPO may supply electric power to the EV
depending on the verification result (S1140).
[0173] Here, the last certificate in the certificate chain may be
the cross certificate issued by the second V2G root CA.
[0174] The public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue the last
certificate except for the cross certificate in the certificate
chain. The certification authority having issued the last
certificate other than the cross certificate in the certificate
chain may be the first V2G root CA or the CPO.
[0175] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself. Alternatively, the
second V2G root CA may indirectly issue the cross certificate for
the first V2G root CA via another device such as the other V2G root
CA or the intermediating device.
[0176] FIG. 12 is a block diagram of a cross certification
apparatus according to an exemplary embodiment of the present
disclosure.
[0177] The cross certification apparatus shown in FIG. 12 may be
implemented in the EV that needs to receive electric power from the
EVSE associated with the CPO having established a trust
relationship with the first V2G root CA. It is assumed that the EV
has established a trust relationship with the second V2G root
CA.
[0178] The cross certification apparatus 100 may include at least
one processor 110, a memory 120 for storing at least one program
instruction to be executed by the processor 110, and a data
transceiver 130 configure to perform communications through a
network.
[0179] The processor 110 may execute program instructions stored in
the memory 120. The processor 110 may include a central processing
unit (CPU) or a graphics processing unit (GPU), or may be
implemented by another kind of dedicated processor suitable for
performing the methods of the present disclosure. The memory 120
may include, for example, a volatile memory such as a read only
memory (ROM) and a nonvolatile memory such as a random access
memory (RAM).
[0180] The data transceiver 130 may include an EVCC communicating
with the SECC of the EVSE provided by the CPO.
[0181] The at least one program instructions may include:
instructions configured to request charging from the EVSE;
instructions configured to receive a certificate chain maintained
by the EVSE from the EVSE; and instructions configured to verify
whether the last certificate in the certificate chain has been
signed by the second V2G root CA.
[0182] The last certificate in the certificate chain may be the
cross certificate issued by the second V2G root CA.
[0183] The public key in the cross certificate may coincide with a
public key corresponding to a private key used to issue the last
certificate except for the cross certificate in the certificate
chain. The certification authority having issued the last
certificate other than the cross certificate in the certificate
chain may be the first V2G root CA or the CPO.
[0184] The second V2G root CA may directly issue the cross
certificate for the first V2G root CA by itself. Alternatively, the
second V2G root CA may indirectly issue the cross certificate via
another device such as the other V2G root CA or the intermediating
device.
[0185] The cross certification method of the present disclosure
described above based on exemplary embodiments enables to manage
the trusts flexibly in the EV charging network or system.
[0186] The apparatus and method according to exemplary embodiments
of the present disclosure may be implemented by computer-readable
program codes or instructions stored on a non-transitory
computer-readable recording medium. The non-transitory
computer-readable recording medium includes all types of recording
media storing data readable by a non-transitory computer system.
The computer-readable recording medium may be distributed over
computer systems connected through a network so that a
computer-readable program or code may be stored and executed in a
distributed manner.
[0187] The non-transitory computer-readable recording medium may
include a hardware device specially configured to store and execute
program commands, such as ROM, RAM, and flash memory. The program
commands may include not only machine language codes such as those
produced by a compiler, but also high-level language codes
executable by a computer using an interpreter or the like.
[0188] Some aspects of the present disclosure have been described
above in the context of a device but may be described using a
method corresponding thereto. In particular, blocks or the device
corresponds to operations of the method or characteristics of the
operations of the method. Similarly, aspects of the present
disclosure described above in the context of a method may be
described using blocks or items corresponding thereto or
characteristics of a device corresponding thereto. Some or all of
the operations of the method may be performed, for example, by (or
using) a hardware device such as a microprocessor, a programmable
computer or an electronic circuit. In some exemplary embodiments,
at least one of most important operations of the method may be
performed by such a device.
[0189] In some exemplary embodiments, a programmable logic device
such as a field-programmable gate array may be used to perform some
or all of functions of the methods described herein. In some
exemplary embodiments, the field-programmable gate array may be
operated with a microprocessor to perform one of the methods
described herein. In general, the methods of the present disclosure
are preferably performed by a certain hardware device.
[0190] The description of the disclosure is merely exemplary in
nature and, thus, variations that do not depart from the substance
of the disclosure are intended to be within the scope of the
disclosure. Such variations are not to be regarded as a departure
from the spirit and scope of the disclosure. Thus, it will be
understood by those of ordinary skill in the art that various
changes in form and details may be made without departing from the
spirit and scope as defined by the following claims.
* * * * *