LAMPS Working Group H. Brockhaus
Internet-Draft Siemens
Intended status: Standards Track D. Goltzsche
Expires: 18 August 2025 Siemens Mobility
14 February 2025
X.509 Certificate Extended Key Usage (EKU) for Automation
draft-ietf-lamps-automation-keyusages-05
Abstract
RFC 5280 defines the ExtendedKeyUsage extension and several extended
key purpose identifiers (KeyPurposeIds) for use with that extension
in X.509 certificates. This document defines KeyPurposeIds for
general-purpose and trust anchor configuration files, for software
and firmware update packages, and for safety-critical communication
to be included in the Extended Key Usage (EKU) extension of X.509 v3
public key certificates used by industrial automation and the
Europe's Rail Joint Undertaking (ERJU) System Pillar.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 18 August 2025.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
Brockhaus & Goltzsche Expires 18 August 2025 [Page 1]
Internet-Draft EKU for Automation February 2025
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4
3. Extended Key Purpose for Automation . . . . . . . . . . . . . 5
4. Including the Extended Key Purpose in Certificates . . . . . 6
5. Implications for a Certification Authority . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 8
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. ASN.1 Module . . . . . . . . . . . . . . . . . . . . 11
Appendix B. History of Changes . . . . . . . . . . . . . . . . . 12
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Automation hardware and software products will strategically be more
safe and secure by fulfilling mandatory, generic system requirements
related to cyber security driven by federal offices like the European
Union Cyber Resilience Act [EU-CRA] governed by the European
Commission and the High Representative of the Union for Foreign
Affairs and Security Policy. Automation products connected to the
internet would bear the so called CE marking [CE-marking] to indicate
they comply. Such regulation was announced in the 2020 EU
Cybersecurity Strategy [EU-STRATEGY], and complements other
legislation in this area, specifically the NIS2 Framework, Directive
on measures for a high common level of cybersecurity across the Union
[NIS2]. 2020 EU Cybersecurity Strategy suggests to implement and
extend international standards such as the Security for industrial
automation and control systems - Part 4-2: Technical security
requirements for IACS components [IEC.62443-4-2] (IACS refers to
industrial automation and control system) and the Industrial
communication networks - Network and system security - Part 3-3:
System security requirements and security levels [IEC.62443-3-3].
Automation hardware and software products of diverse vendors that are
connected on automation networks and the internet build common
automation solutions. Harmonized attributes would allow transparency
of security properties and interoperability for vendors in context of
secure software and firmware updates, general-purpose configuration,
Brockhaus & Goltzsche Expires 18 August 2025 [Page 2]
Internet-Draft EKU for Automation February 2025
trust anchor configuration, and secure safety communication.
A concrete example for Automation is a Rail Automation system. The
Europe's Rail Joint Undertaking System Pillar [ERJU] will deliver a
unified operational concept and a functional, safe, and secure system
architecture with system requirements for Rail Automation. The
deliverables include due consideration of cyber security aspects
based on the IEC 62443 series of standards, focused on the European
railway network to which Directive 2016/797 - Interoperability of the
rail system within the EU [Directive-2016_797] applies.
The ERJU System Pillar Cyber Security Working Group makes use of PKIs
to generate X.509 PKI certificates. The certificates are used for
the following purposes, among others:
* Validating signatures of general-purpose software configuration
files.
* Validating signatures of trust anchor configuration files.
* Validating signatures of software and firmware update packages.
* Authenticating communication endpoints authorized for safety-
critical communication.
[RFC5280] specifies several extended key usages, defined via
KeyPurposeIds, for X.509 certificates. KeyPurposeIds added to a
certificate are meant to express intent as to the purpose of the
named usage, for humans and for complying libraries. In addition,
the IANA registry "SMI Security for PKIX Extended Key Purpose"
[RFC7299] contains additional KeyPurposeIds. The use of the
anyExtendedKeyUsage KeyPurposeId, as defined in Section 4.2.1.12 of
[RFC5280], is generally considered a poor practice. This is
especially true for certificates, whether they are multi-purpose or
single-purpose, within the context of ERJU System Pillar.
If the purpose of the issued certificates is not restricted, i.e.,
the type of operations for which a public key contained in the
certificate can be used in unintended ways, increasing the risk of
cross-application attacks. Failure to ensure proper segregation of
duties means that an application or system that generates the public/
private keys and applies for a certificate to the operator
certification authority could obtain a certificate that can be
misused for tasks that this application or system is not entitled to
perform. For example, management of trust anchors is a particularly
critical task. A device could potentially accept a trust anchor
configuration file signed by a service that uses a certificate with
no EKU or with the KeyPurposeId id-kp-codeSigning (Section 4.2.1.12
Brockhaus & Goltzsche Expires 18 August 2025 [Page 3]
Internet-Draft EKU for Automation February 2025
of [RFC5280]) or id-kp-documentSigning [RFC9336]. A device should
only accept trust anchor configuration files if the file is verified
with a certificate that has been explicitly issued for this purpose.
The KeyPurposeId id-kp-serverAuth (Section 4.2.1.12 of [RFC5280]) can
be used to identify that the certificate is for a TLS WWW server, and
the KeyPurposeId id-kp-clientAuth (Section 4.2.1.12 of [RFC5280]) can
be used to identify that the certificate is for a TLS WWW client.
However, there are currently no KeyPurposeIds for usage with X.509
certificates for safety-critical communication.
This document addresses the above problems by defining keyPurposeIds
for the EKU extension of X.509 public key certificates. These
certificates are either used for signing files (general-purpose
configuration and trust anchor configuration files, software and
firmware update packages) or are used for safety-critical
communication.
Vendor-defined KeyPurposeIds used within a PKI governed by the vendor
or a group of vendors typically do not pose interoperability
concerns, as non-critical extensions can be safely ignored if
unrecognized. However, using KeyPurposeIds outside of their intended
vendor-controlled environment or in ExtendedKeyUsage extensions that
have been marked critical can lead to interoperability issues.
Therefore, it is advisable not to rely on vendor-defined
KeyPurposeIds. Instead, the specification defines standard
KeyPurposeIds to ensure interoperability across various vendors and
industries.
Although the specification focuses on use in industrial automation,
the definitions are intentionally broad to allow the use of the
KeyPurposeIds defined in this document in other deployments as well.
The context in which the KeyPurposeIds defined in this document are
used is out of scope for this document. In other words, details must
be described in technical standards and certificate policies for
those implementations.
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 4]
Internet-Draft EKU for Automation February 2025
3. Extended Key Purpose for Automation
This specification defines the KeyPurposeIds id-kp-configSigning, id-
kp-trustAnchorConfigSigning, id-kp-updatePackageSigning, and id-kp-
safetyCommunication and uses these, respectively, for: signing
general-purpose configuration files or trust anchor configuration
files, signing software or firmware update packages, or
authenticating communication peers for safety-critical communication.
As described in Section 4.2.1.12 of [RFC5280], "[i]f the [extended
key usage] extension is present, then the certificate MUST only be
used for one of the purposes indicated" and "[i]f multiple [key]
purposes are indicated the application need not recognize all
purposes indicated, as long as the intended purpose is present".
None of the KeyPurposeIds specified in this document are
intrinsically mutually exclusive. Instead, the acceptable
combinations of those KeyPurposeIds with others specified in this
document and with other KeyPurposeIds specified elsewhere are left to
the technical standards of the respective application and the
certificate policy of the respective PKI. For example, a technical
standard may specify: 'Different keys and certificates MUST be used
for safety communication and for trust anchor updates, and a relying
party MUST ignore the KeyPurposeId id-kp-trustAnchorConfigSigning if
id-kp-safetyCommunication is one of the specified key purposes in a
certificate.' The certificate policy for example may specify: 'The
id-kp-safetyCommunication KeyPuposeId SHOULD NOT be included in an
issued certificate together with the KeyPurposeId id-kp-
trustAnchorConfigSigning.' Technical standards and certificate
policies of different applications may specify other rules. Further
considerations on prohibiting combinations of KeyPurposeIds is
described in the Security Considerations section of this document.
Systems or applications that verify the signature of a general-
purpose configuration file or trust anchor configuration file, the
signature of a software or firmware update package, or the
authentication of a communication peer for safety-critical
communication SHOULD require that corresponding KeyPurposeIds be
specified by the EKU extension. If the certificate requester knows
the certificate users are mandated to use these KeyPurposeIds, it
MUST enforce their inclusion. Additionally, such a certificate
requester MUST ensure that the KeyUsage extension be set to
digitalSignature for signature verification, to keyEncipherment for
public key encryption, and keyAgreement for key agreement.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 5]
Internet-Draft EKU for Automation February 2025
4. Including the Extended Key Purpose in Certificates
[RFC5280] specifies the EKU X.509 certificate extension for use on
end entity certificates. The extension indicates one or more
purposes for which the certified public key is valid. The EKU
extension can be used in conjunction with the Key Usage (KU)
extension, which indicates the set of basic cryptographic operations
for which the certified key may be used. The EKU extension syntax is
repeated here for convenience:
ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
KeyPurposeId ::= OBJECT IDENTIFIER
As described in [RFC5280], the EKU extension may, at the option of
the certificate issuer, be either critical or non-critical. The
inclusion of KeyPurposeIds id-kp-configSigning, id-kp-
trustAnchorConfigSigning, id-kp-updatePackageSigning, and id-kp-
safetyCommunication in a certificate indicates that the public key
encoded in the certificate has been certified for the following
usages:
* id-kp-configSigning
A public key contained in a certificate containing the
KeyPurposeId id-kp-configSigning may be used for verifying
signatures of general-purpose configuration files of various
formats (for example XML, YAML, or JSON). Configuration files are
used to configure hardware or software.
* id-kp-trustAnchorConfigSigning
A public key contained in a certificate containing the
KeyPurposeId id-kp-trustAnchorConfigSigning may be used for
verifying signatures of trust anchor configuration files of
various formats (for example XML, YAML, or JSON). Trust anchor
configuration files are used to add or remove trust anchors to the
trust store of a device.
* id-kp-updatePackageSigning
A public key contained in a certificate containing the
KeyPurposeId id-kp-updatePackageSigning may be used for verifying
signatures of secure software or firmware update packages. Update
packages are used to install software (including bootloader,
firmware, safety-related applications, and others) on systems.
* id-kp-safetyCommunication
Brockhaus & Goltzsche Expires 18 August 2025 [Page 6]
Internet-Draft EKU for Automation February 2025
A public key contained in a certificate containing the
KeyPurposeId id-kp-safetyCommunication may be used to authenticate
a communication peer for safety-critical communication based on
TLS or other protocols.
id-kp OBJECT IDENTIFIER ::=
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) 3 }
id-kp-configSigning OBJECT IDENTIFIER ::= { id-kp 41 }
id-kp-trustAnchorConfigSigning OBJECT IDENTIFIER ::= { id-kp 42 }
id-kp-updatePackageSigning OBJECT IDENTIFIER ::= { id-kp 43 }
id-kp-safetyCommunication OBJECT IDENTIFIER ::= { id-kp 44 }
5. Implications for a Certification Authority
The procedures and practices employed by a certification authority
MUST ensure that the correct values for the EKU extension as well as
the KU extension are inserted in each certificate that is issued.
The inclusion of the id-kp-configSigning, id-kp-
trustAnchorConfigSigning, id-kp-updatePackageSigning, and id-kp-
safetyCommunication KeyPurposeIds does not preclude the inclusion of
other KeyPurposeIds.
6. Security Considerations
The Security Considerations of [RFC5280] are applicable to this
document. These extended key usage key purposes do not introduce new
security risks but instead reduce existing security risks by
providing the means to identify if the certificate is generated to
verify the signature of a general-purpose or trust anchor
configuration file, the signature of a software or firmware update
package, or the authentication of a communication peer for safety-
critical communication.
To reduce the risk of specific cross-protocol attacks, the relying
party or the relying party software may additionally prohibit use of
specific combinations of KeyPurposeIds. The procedure for allowing
or disallowing combinations of KeyPurposeIds using excluded
KeyPurposeId and permitted KeyPurposeId, as carried out by a relying
party, is defined in Section 4 of [RFC9336]. The technical standards
and certificate policies of the application should specify concrete
requirements for excluded or permitted KeyPurposeIds or their
combinations. An example of excluded KeyPurposeIds can be the
presence of the anyExtendedKeyUsage KeyPurposeId. Examples of
allowed KeyPurposeIds combinations can be the presence of id-kp-
safetyCommunication together with id-kp-clinetAuth or id-kp-
serverAuth.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 7]
Internet-Draft EKU for Automation February 2025
7. Privacy Considerations
In some security protocols, such as TLS 1.2 [RFC5246], certificates
are exchanged in the clear. In other security protocols, such as TLS
1.3 [RFC8446], the certificates are encrypted. The inclusion of the
EKU extension can help an observer determine the purpose of the
certificate. In addition, if the certificate is issued by a public
certification authority, the inclusion of an EKU extension can help
an attacker to monitor the Certificate Transparency logs [RFC9162] to
identify the purpose of the certificate.
8. IANA Considerations
IANA is requested to register the following ASN.1 [X.680] module OID
in the "SMI Security for PKIX Module Identifier" registry
(1.3.6.1.5.5.7.0). This OID is defined in Appendix A.
+=========+=======================+============+
| Decimal | Description | References |
+=========+=======================+============+
| TBD1 | id-mod-automation-eku | This-RFC |
+---------+-----------------------+------------+
Table 1
IANA is also requested to register the following OIDs in the "SMI
Security for PKIX Extended Key Purpose" registry (1.3.6.1.5.5.7.3).
These OIDs are defined in Section 4.
+=========+================================+============+
| Decimal | Description | References |
+=========+================================+============+
| 41 | id-kp-configSigning | This-RFC |
+---------+--------------------------------+------------+
| 42 | id-kp-trustAnchorConfigSigning | This-RFC |
+---------+--------------------------------+------------+
| 43 | id-kp-updatePackageSigning | This-RFC |
+---------+--------------------------------+------------+
| 44 | id-kp-safetyCommunication | This-RFC |
+---------+--------------------------------+------------+
Table 2
9. Acknowledgments
We would like to thank the authors of [RFC9336] and [RFC9509] for
their excellent template.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 8]
Internet-Draft EKU for Automation February 2025
We also thank all reviewers of this document for their valuable
feedback.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/rfc/rfc5280>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[X.680] ITU-T, "Information Technology - Abstract Syntax Notation
One (ASN.1): Specification of basic notation", ITU-T
Recommendation X.680 , February 2021,
<https://www.itu.int/rec/T-REC.X.680>.
[X.690] ITU-T, "Information Technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules
(DER)", ITU-T Recommendation X.690 , February 2021,
<https://www.itu.int/rec/T-REC.X.690>.
10.2. Informative References
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/rfc/rfc5246>.
[RFC7299] Housley, R., "Object Identifier Registry for the PKIX
Working Group", RFC 7299, DOI 10.17487/RFC7299, July 2014,
<https://www.rfc-editor.org/rfc/rfc7299>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 9]
Internet-Draft EKU for Automation February 2025
[RFC9162] Laurie, B., Messeri, E., and R. Stradling, "Certificate
Transparency Version 2.0", RFC 9162, DOI 10.17487/RFC9162,
December 2021, <https://www.rfc-editor.org/rfc/rfc9162>.
[RFC9336] Ito, T., Okubo, T., and S. Turner, "X.509 Certificate
General-Purpose Extended Key Usage (EKU) for Document
Signing", RFC 9336, DOI 10.17487/RFC9336, December 2022,
<https://www.rfc-editor.org/rfc/rfc9336>.
[RFC9509] Reddy.K, T., Ekman, J., and D. Migault, "X.509 Certificate
Extended Key Usage (EKU) for 5G Network Functions",
RFC 9509, DOI 10.17487/RFC9509, March 2024,
<https://www.rfc-editor.org/rfc/rfc9509>.
[Directive-2016_797]
European Parliament, Council of the European Union,
"Directive 2016/797 - Interoperability of the rail system
within the EU", May 2020,
<https://eur-lex.europa.eu/eli/dir/2016/797/2020-05-28>.
[ERJU] Europe's Rail Joint Undertaking, "SP-Cybersecurity-
SharedCybersecurityServices - Review 3 Final Draft Specs
(V0.90)", September 2024, <https://rail-
research.europa.eu/wp-content/uploads/2023/10/
ERJU_SP_CyberSecurity_Review3_Files.zip>.
[EU-CRA] European Commission, "Proposal for a REGULATION OF THE
EUROPEAN PARLIAMENT AND OF THE COUCIL on horizontal
cybersecurity requirements for products with digital
elements and amending Regulation (EU) 2019/1020",
September 2022, <https://digital-
strategy.ec.europa.eu/en/library/cyber-resilience-act>.
[EU-STRATEGY]
European Commission, "The EU's Cybersecurity Strategy for
the Digital Decade", December 2020, <https://digital-
strategy.ec.europa.eu/en/library/eus-cybersecurity-
strategy-digital-decade-0>.
[NIS2] European Commission, "Directive (EU) 2022/2555 of the
European Parliament and of the Council", December 2024,
<https://digital-strategy.ec.europa.eu/en/policies/
nis2-directive>.
Brockhaus & Goltzsche Expires 18 August 2025 [Page 10]
Internet-Draft EKU for Automation February 2025
[IEC.62443-4-2]
IEC, "Security for industrial automation and control
systems - Part 4-2: Technical security requirements for
IACS components", IEC 62443-4-2:2019 , February 2019,
<https://webstore.iec.ch/publication/34421>.
[IEC.62443-3-3]
IEC, "Industrial communication networks - Network and
system security - Part 3-3: System security requirements
and security levels", IEC 62443-3-3:2013 , August 2013,
<https://webstore.iec.ch/publication/7033>.
[CE-marking]
European Commission, "CE marking", n.d., <https://single-
market-economy.ec.europa.eu/single-market/ce-marking_en>.
Appendix A. ASN.1 Module
The following module adheres to ASN.1 specifications [X.680] and
[X.690].
<CODE BEGINS>
Automation-EKU
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-eu-automation-eku (TBD1) }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
-- OID Arc
id-kp OBJECT IDENTIFIER ::=
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) kp(3) }
-- Extended Key Usage Values
id-kp-configSigning OBJECT IDENTIFIER ::= { id-kp 41 }
id-kp-trustAnchorConfigSigning OBJECT IDENTIFIER ::= { id-kp 42 }
id-kp-updatePackageSigning OBJECT IDENTIFIER ::= { id-kp 43 }
id-kp-safetyCommunication OBJECT IDENTIFIER ::= { id-kp 44 }
END
<CODE ENDS>
Brockhaus & Goltzsche Expires 18 August 2025 [Page 11]
Internet-Draft EKU for Automation February 2025
Appendix B. History of Changes
[RFC Editor: Please remove this appendix in the release version of
the document.]
Changes from 04 -> 05:
* Addressed SECDIR review comments from Carl Wallace
Changes from 03 -> 04:
* Addressed Deb's AD review comments (see "AD Comments on draft-
ietf-lamps-automation-keyusages")
* Added early allocated OIDs
Changes from 02 -> 03:
* Rename id-kp-trustanchorSigning to id-kp-trustAnchorConfigSigning
* Rename id-kp-updateSigning to id-kp-updatePackageSigning
* Fixed some nits
Changes from 01 -> 02:
* Updates Sections 3 and 6 addressing last call comments (see "WG
Last Call for draft-ietf-lamps-automation-keyusages-01")
Changes from 01 -> 02:
* Implemented the changes requested during WGLC
Changes from 00 -> 01:
* Fixed some minor nids and wording issues
draft-ietf-lamps-automation-keyusages version 00:
* Updated document and filename after WG adoption
Changes from 00 -> 01:
* Updated last paragraph of Section 1 addressing WG adoption
comments by Rich and Russ
* Updated name and OID of ASN.1 module
Brockhaus & Goltzsche Expires 18 August 2025 [Page 12]
Internet-Draft EKU for Automation February 2025
draft-brockhaus-lamps-automation-keyusages version 00:
* Broadened the scope to general automation use case and use ERJU as
an example.
* Fixed some nits reported.
draft-brockhaus-lamps-eu-rail-keyusages version 00:
* Initial version of the document following best practices from RFC
9336 and RFC 9509
Contributors
Szofia Fazekas-Zisch
Siemens AG Digital Industries Factory Automation
Breslauer Str. 5
90766 Fuerth
Germany
Email: szofia.fazekas-zisch@siemens.com
URI: https://www.siemens.com
Baptiste Fouques
Alstom
Email: baptiste.fouques@alstomgroup.com
Daniel Gutierrez Orta
CAF Signalling
Email: daniel.gutierrez@cafsignalling.com
Martin Weller
Hitachi Rail
Email: martin.weller@urbanandmainlines.com
Nicolas Poyet
SNCF
Email: nicolas.poyet@sncf.fr
Authors' Addresses
Brockhaus & Goltzsche Expires 18 August 2025 [Page 13]
Internet-Draft EKU for Automation February 2025
Hendrik Brockhaus
Siemens
Werner-von-Siemens-Strasse 1
80333 Munich
Germany
Email: hendrik.brockhaus@siemens.com
URI: https://www.siemens.com
David Goltzsche
Siemens Mobility
Ackerstrasse 22
38126 Braunschweig
Germany
Email: david.goltzsche@siemens.com
URI: https://www.mobility.siemens.com
Brockhaus & Goltzsche Expires 18 August 2025 [Page 14]