IEC TS 62351-3:2007

TECHNICAL IEC
SPECIFICATION TS 62351-3
First edition
2007-06
Power systems management and
associated information exchange –
Data and communications security –
Part 3:
Communication network and system security –
Profiles including TCP/IP
Reference number
IEC/TS 62351-3:2007(E)
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TECHNICAL IEC
SPECIFICATION TS 62351-3
First edition
2007-06
Power systems management and
associated information exchange –
Data and communications security –
Part 3:
Communication network and system security –
Profiles including TCP/IP
PRICE CODE
Commission Electrotechnique Internationale K

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – TS 62351-3 © IEC:2007(E)
CONTENTS
FOREWORD.3

1 Scope and object.5
1.1 Scope.5
1.2 Object .5
2 Normative references .6
3 Terms and definitions .6
4 Security issues addressed by this technical specification.6
4.1 Operational requirements affecting the use of TLS in the telecontrol
environment .6
4.2 Security threats countered.7
4.3 Attack methods countered .7
5 Mandatory requirements .7
5.1 Deprecation of non-encrypting cipher suites .7
5.2 Negotiation of versions.7
5.3 Cipher renegotiation .7
5.4 Message authentication code .8
5.5 Certificate support.8
5.5.1 Multiple Certificate Authorities (CAs) .8
5.5.2 Certificate size .8
5.5.3 Certificate exchange.8
5.5.4 Certificate comparison.8
5.6 Co-existence with non-secure protocol traffic .9
6 TC 57 referencing standard requirements.9
7 Conformance.10

TS 62351-3 © IEC:2007(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
__________
POWER SYSTEMS MANAGEMENT AND ASSOCIATED
INFORMATION EXCHANGE –
DATA AND COMMUNICATIONS SECURITY –

Part 3: Communication network and system security –
Profiles including TCP/IP
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
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The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• The subject is still under technical development or where, for any other reason, there is
the future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62351-3, which is a technical specification, has been prepared by IEC technical
committee 57: Power systems management and associated information exchange.

– 4 – TS 62351-3 © IEC:2007(E)

The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
57/803/DTS 57/857/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62351 series, published under the general title Power systems
management and associated information exchange – Data and communications security, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

TS 62351-3 © IEC:2007(E) – 5 –
POWER SYSTEMS MANAGEMENT AND ASSOCIATED
INFORMATION EXCHANGE –
DATA AND COMMUNICATIONS SECURITY –

Part 3: Communication network and system security –
Profiles including TCP/IP
1 Scope and object
1.1 Scope
This part of IEC 62351, which is a technical specification, specifies how to provide
confidentiality, tamper detection, and message level authentication for SCADA and telecontrol
protocols that make use of TCP/IP as a message transport layer.
Although there are many possible solutions to secure TCP/IP, the particular scope of this part
is to provide security between communicating entities at either end of a TCP/IP connection
within the end communicating entities. The use and specification of intervening external
security devices (e.g. “bump-in-the-wire”) are considered outside the scope of this technical
specification.
1.2 Object
This part of IEC 62351 specifies how to secure TCP/IP-based protocols through constraints
on the specification of the messages, procedures, and algorithms of Transport Layer Security
(TLS) (defined in RFC 2246) so that they are applicable to the telecontrol environment of
IEC TC 57. It is intended that this specification be referenced as a normative part of other IEC
TC 57 standards that have the need for providing security for their TCP/IP-based protocol.
However, it is up to the individual protocol security initiatives to decide if this technical
specification is to be referenced.
This part reflects the security requirements of the IEC TC 57 protocols. Should other
standards bring forward new requirements, this specification may need to be revised.
The initial audience for this specification is intended to be the members of the working groups
developing or making use of the protocols within IEC TC 57. For the measures described in
this specification to take effect, they must be accepted and referenced by the specifications
for the protocols themselves, where the protocols make use of TCP/IP. This specification is
written to enable that process.
The subsequent audience for this specification is intended to be the developers of products
that implement these protocols.
Portions of this specification may also be of use to managers and executives in order to
understand the purpose and requirements of the work.

– 6 – TS 62351-3 © IEC:2007(E)
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 62351-1, Power systems management and associated information exchange – Data and
communications security – Part 1: Communication network and system security – Introduction
to security issues
IEC 62351-2, Power systems management and associated information exchange – Data and
communications security – Part 2: Glossary of terms
1)
RFC 2246:1999, The TLS Protocol Version 1.0
2)
RFC 2712:1999, Addition of Kerberos Cipher Suites to Transport Layer Security (TLS)
RFC 3268, 2002, Advanced Encryption Standard (AES) Ciphersuites for Transport Layer
Security (TLS)
RFC 3280, 2002, Internet X.509 Public Key Infrastructure Certificate and Certificate
Revocation List (CRL) Profile
3 Terms and definitions
For the purposes of this document, the terms and definitions contained in IEC 62351-2 apply.
4 Security issues addressed by this technical specification
4.1 Operational requirements affecting the use of TLS in the telecontrol environment
The IEC TC 57 telecontrol environment has different operational requirements than many
information technology (IT) protocols that make use of TLS
...