ETSI TR 101 053-2 V2.2.2 (2008-09)

ETSI TR 101 053-2 V2.2.2 (2008-09)
Technical Report


Security Algorithms Group of Experts (SAGE);
Rules for the management of the TETRA standard
encryption algorithms;
Part 2: TEA2

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2 ETSI TR 101 053-2 V2.2.2 (2008-09)



Reference
RTR/SAGE-00025-2
Keywords
algorithm, security, TETRA
ETSI
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3 ETSI TR 101 053-2 V2.2.2 (2008-09)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
2.1 Normative references.6
2.2 Informative references.6
3 Definitions and abbreviations.6
3.1 Definitions.6
3.2 Abbreviations.6
4 TEA2 management structure.7
5 Use of TEA2.8
5.1 Users of TEA2.8
5.2 TEA2 States and Territories .8
6 Distribution procedures .9
6.1 Distribution by TEA2 custodian.9
6.2 Transfers by a licencee .10
6.3 Distribution of TETRA equipment containing TEA2 through a third party.10
6.4 Third party operator supplying TETRA services with TEA2.10
6.5 Use of TEA2 by a secondary user .11
6.6 Distribution of TEA2 specification part 3 by the TEA2 custodian .11
7 Approval criteria and restrictions .11
8 The TEA2 custodian.12
8.1 Responsibilities .12
8.2 Appointment.13
Annex A: Items delivered to approved recipient of TEA2 .14
Annex B: Confidentiality and Restricted Usage Undertaking for Manufacturers of TEA2.15
Annex C: Confidentiality and Restricted Usage Undertaking for Users of TEA2.18
Annex D: Confidentiality and Restricted Usage Undertaking for Suppliers.21
Annex E: TEA2 State and Territories list .23
History .24

ETSI

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4 ETSI TR 101 053-2 V2.2.2 (2008-09)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by Advisory Committee Security Algorithms Group of Experts (SAGE).
The present document is part 2 of a multi-part deliverable covering Rules for the management of the TETRA standard
encryption algorithms, as identified below:
Part 1: "TEA1";
Part 2: "TEA2";
Part 3: "TEA3";
Part 4: "TEA4".
ETSI

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5 ETSI TR 101 053-2 V2.2.2 (2008-09)
1 Scope
The purpose of the present document is to specify the rules for the management of the TETRA standard encryption
algorithm TEA2. This algorithm is intended for air interface encryption in TETRA products.
The specification for TEA2 consists of the following three parts:
Part 1: Algorithm specification;
Part 2: Design conformance test data;
Part 3: Algorithm input/output test data.
The procedures described in the present document apply to parts 1 and 2 of the specifications. The parts 1 and 2 are
confidential.
Part 3 of each of the specifications is not confidential and can be obtained directly from the TEA2 Custodian
(see clause 6.5). There are no restrictions on the distribution of this part of the specifications.
The management structure is defined in clause 4. This structure is defined in terms of the principals involved in the
management of TEA2 (ETSI, ETSI Technical Committee TETRA, TEA2 Custodian and approved recipients) together
with the relationships and interactions between them.
Clause 5 is concerned with the rules for the use of TEA2. This clause is supplemented by clause E in which the states
and territories are listed in which a User can become an approved recipient.
The procedures for delivering TEA2 to approved recipients are defined in clause 6. This clause is supplemented by
clause A that specifies the items that are to be delivered.
Clause 7 is concerned with the criteria for approving an organization for receipt of TEA2 deliverables and with the
responsibilities of an approved recipient. This clause is supplemented by clauses B, C and D which contain a
Confidentiality and Restricted Usage Undertaking to be signed by each approved recipient Manufacturer, User and
Third Party Supplier.
Clause 8 is concerned with the appointment and responsibilities of the TEA2 Custodian.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
ETSI

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6 ETSI TR 101 053-2 V2.2.2 (2008-09)
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ETSI EN 300 392-7: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 7: Security".
[i.2] ETSI ETS 300 396-6: "Terrestrial Trunked Radio (TETRA); Direct Mode Operation (DMO);
Part 6: Security".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
manufacturer: bona fide designer or manufacturer of TETRA subscriber or fixed systems where TETRA Standard
Algorithm TEA2 is included in the systems; or a bona fide designer or manufacturer of components for TETRA
subscriber or fixed systems where at least one of the components includes TEA2; or a bona fide designer or
manufacturer of TETRA system simulator for approval testing of TETRA subscriber or fixed systems where the
simulator includes TEA2
primary user: governmental organization for a TETRA network that is primarily used by public safety organizations in
their own state or territory
secondary user: military organization in a state or territory where there is no primary user with approval to operate a
TETRA network given by the governmental organization that is responsible for public safety
supplier: supplier of TETRA subscriber or fixed systems in which TEA2 is included or of TETRA system simulators in
which TEA2 is included, or a third party operator supplying TETRA services with TEA2 to a primary and/or secondary
user
third-party operator: user who is not a primary or secondary user who is supplying TETRA services with TEA2 to
primary and/or secondary users
user: primary or secondary user
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CRUU Confidentiality and Restricted Usage Undertaking
SFPG Security and Fraud Prevention Group
SwMI Switching and Management Infrastructure
TEA2 TETRA Standard Encryption Algorithm 2
ETSI

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7 ETSI TR 101 053-2 V2.2.2 (2008-09)
TETRA TErrestrial Trunked RAdio
4 TEA2 management structure
The management structure is depicted in figure 1.

A p p r o v e d r e c i p i e n t o f T EA 2

1 4
3 5 8
TE A 2 C u s t o d i a n

2 6 7
A p p r o v a l TEA 2 T E A 2
a b
r e g i s t e r
f i l e
c r i te r i a
d
c
E T S I / E T S I TC TETRA




NOTE: Key:
a  = Agreement between TEA2 Custodian and ETSI
b  = Status reports and recommendations
c  = Setting of approval criteria

d  = Restricted details of the TEA2 register
1  = Request for TEA2
2  = Check of request against approval criteria
3 and 4 = Exchange of Confidentiality and Restricted Usage Undertaking
5  = Dispatch of TEA2 specification
6  = Update the TEA2 register
7  = Document filing
8  = Technical advice

Figure 1: TEA2 management structure
Figure 1 shows the three principles involved in the management of TEA2 and the relationships and interactions between
them.
ETSI is the owner of the TEA2. ETSI Technical Committee TETRA sets the approval criteria for receipt of the
algorithm (see clause 7).

The TEA2 Custodian is the interface between ETSI and the approved recipients of the TEA2.
The Custodian is as identified in clause 8.2 of the present document. The TEA2 Custodian's duties are detailed in
clause 8. They include distributing TEA2 to approved recipients, as detailed in clause 7, providing limited technical
advice to approved recipients and providing algorithm status reports to ETSI Technical Committee TETRA.
ETSI

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8 ETSI TR 101 053-2 V2.2.2 (2008-09)
5 Use of TEA2
5.1 Users of TEA2
A TEA2 User License is given to a governmental organization for a TETRA network that is primarily used by public
safety organizations (see note) in their own state or territory. A TETRA network may consist of fixed base stations and
SwMI, all located in the home state or territory, and/or one or more base stations and SwMIs that may also be used
outside the home state or territory if both base stations and SwMIs are controlled from the home state or territory. A
governmental organization that obtains a TEA2 User License under these conditions is referred to as a primary user of
TEA2.
NOTE 1: Public safety organizations are e.g. Police, Fire brigade, Customs and Excise, Ambulance and Emergency
Medical Service, Coastguard.
NOTE 2: There may be more than one primary user in any allowed state and the number of primary users is a
national option.
It is to be decided by the primary user of TEA2, who has received a TEA2 User License from TEA2 custodian, which
user organizations can use the above-mentioned network. This may be done on the basis of a sublicensing procedure
that may also be needed for the procurement of mobile terminals or movable equipment by a user organization.
A primary user can approve the use of TEA2 in a TETRA network owned by a military organization that is operational
in the same state or territory as the primary user. In the case where there is no primary user in that state or territory the
military organization has to demonstrate written approval to operate a TETRA network given by the governmental
organization that is responsible for public safety. Such military organizations are referred to as secondary users. Also in
these cases a TETRA network may consist of fixed base stations and SwMI, all located in the home state or territory,
and/or one or more base stations and SwMIs that may also be used outside the home state or territory if both base
stations and SwMIs are controlled from the home state or territory.
It is to be decided by the secondary user of TEA2, which has received a TEA2 User License from the TEA2 custodian,
those user organizations that can use the above-mentioned network. This may be done on the basis of a sublicensing
procedure that may also be needed for the procurement of mobile terminals or movable equipment by a user
organization.
5.2 TEA2 States and Territories
Organizations can be a primary or secondary user of TEA2 when it is based and (normally) operates in a state or
territory that is at least:
a) a Schengen state (see note 1); or
b) a European Union state (see note 2); or
c) a candidate European Union state (see note 3); or
d) a dependent area of one of the Schengen or (candidate) European Union states (but not overseas (see note 4));
or
e) a state (but not overseas) that has a bilateral agreement with the European Union;
f) a state that only has borders with TEA2 states or territories as in point a) through e).
NOTE 1: Including autonomous regions of that state that are also part of Schengen.
NOTE 2: Including autonomous regions of that state that are also part of the European Union.
NOTE 3: Including autonomous regions of that state that are also candidate part of the European Union.
NOTE 4: Overseas Countries and Territories as in Part Four of the Consolidated version of the Treaty establishing
the European Community (2002) plus French overseas territories (French Guyana, Guadeloupe,
Martinique, Réunion).
ETSI

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9 ETSI TR 101 053-2 V2.2.2 (2008-09)
Based on this an initial list of TEA2 states and territories was drafted. This list is added as clause E. The custodian
maintains the actual list of TEA2 states and territories.
6 Distribution procedures
6.1 Distribution by TEA2 custodian
The following procedures for distributing TEA2 to approved recipients are defined with reference to figure 1:
1) The TEA2 Custodian receives a written request for N copies of the TEA2 specification (see note 1) or a
written request for entering in a Confidentiality and Restricted Usage Undertaking for a user or a third party
supplier of TETRA equipment containing TEA2.
2) The TEA2 Custodian indicates whether the requesting organization meets the approval criteria (see clause 7).
3) If the request is approved, the TEA2 Custodian dispatches 2 copies of the corresponding Confidentiality and
Restricted Usage Undertaking (as given in clause B, C or D) for signature by the approved recipient
(see notes 2 and 6) together with a copy of the present document (Rules for the Management of the TETRA
Standard Encryption Algorithm TEA2).
4) Both copies of the Confidentiality and Restricted Usage Undertaking are to be signed by the approved
recipient (see notes 5 and 7) and returned to the TEA2 Custodian, together with the payment of charges (if
any).
5) The TEA2 Custodian sends up to N (see note 3) numbered copies of the TEA2 specification to the approved
recipient and one countersigned copy of the returned Confidentiality and Restricted Usage Undertaking and a
covering letter (see notes 4 and 6).
6) The TEA2 Custodian updates the TEA2 Register by recording the name and address of the recipient, the
numbers of the copies of the TEA2 specification delivered, if any, and the date of delivery. If the original
request is not approved, the TEA2 Custodian records the name and address of the requesting organization and
the reason for rejecting the request in the TEA2 Register (see also note 8).
7) The TEA2 Custodian countersigns and files the second returned copy of the Confidentiality and Restricted
Usage Undertaking in the TEA2 File together with a copy of the covering letter sent to the approved recipient.
8) The TEA2 Custodian may provide very limited technical advice with respect to answering questions
concerning the TEA2 specification.
9) In case an organization cannot comply with the rules as described in the present document the TEA2 custodian
can still decide, on an exceptional basis, to distribute the TEA2 algorithm to this organization. In this case the
TEA2 custodian will inform ETSI SAGE and TC TETRA about his decision and at the same time provide a
motivation. If a special Confidentiality and Restricted Usage Undertaking (i.e. different from clause B, C or D)
is used, the TEA2 custodian will first ask the ETSI Legal Department to approve this Confidentiality and
Restricted Usage Undertaking (CRUU).
NOTE 1: Requests for the TEA2 specification may be made directly to the TEA2 Custodian or through ETSI,
where appropriate.
NOTE 2: The confidentiality and Restricted Usage Undertaking specifies the number of copies requested.
NOTE 3: N may be 0. In case specifications of TEA2 are delivered the covering letter specifies the numbers of the
copies delivered.
NOTE 4: The TEA2 Custodian sends all items listed in clause A. Requests for part of the package of items will be
rejected.
NOTE 5: An organization may request the specification on behalf of a second organization. In this case, the first
organization is responsible for returning a Confidentiality and Restricted Usage Undertaking signed by
the second organization. Refer to the details given in clauses 6.2, 6.3 and 6.4.
ETSI

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10 ETSI TR 101 053-2 V2.2.2 (2008-09)
NOTE 6: Under normal circumstances the Custodian is expected to respond within 25 working days, excluding the
delay of the procedures with the Customs Services.
NOTE 7: The approved recipient is represented by its authorized officers.
NOTE 8: If a TEA2 specification is returned to the TEA2 Custodian (for example the recipient may decide not to
make use of the information), then the TEA2 Custodian destroys the specification and enters a note to this
effect in the TEA2 Register.
6.2 Transfers by a licencee
An organization which has already been approved and has obtained TEA2 specifications may transfer one or more of
these specifications, subject to national legislation, to a second organization which requires the specification.
In this case, the first organization has to ensure that the second organization meets the approval criteria. The first
organization has to get the second organization to sign two copies of the Confidentiality and Restricted Usage
Undertaking for Manufacturers of TEA2 as in clause B. The first organization then sends these to the TEA2 Custodian,
together with the numbers of the specifications that are to be transferred.
The TEA2 Custodian then enters the transfer details in the TEA2 Register, countersigns the Confidentiality and
Restricted Usage Undertakings, returns one of these together with a covering letter to the first organization, and files the
other and a copy of the letter in the TEA2 File.
The first organization is responsible for passing (a copy of) the countersigned Confidentiality and Restricted Usage
Undertaking to the second organization.
6.3 Distribution of TETRA equipment containing TEA2 through
a third party
NOTE: This clause covers the "supplier" licence type.
A TETRA manufacturer that has already been approved and has obtained TEA2 specifications may be allowed, subject
to national legislation, to distribute TETRA equipment containing TEA2 via a third party.
In this case, the TETRA manufacturer has to get the third party to sign two copies of the Confidentiality and Restricted
Usage Undertaking for Suppliers (see clause D). The TETRA manufacturer then sends these to the TEA2 Custodian.
The TEA2 Custodian then enters the transfer details in the TEA2 Register, countersigns the Confidentiality and
Restricted Usage Undertakings, returns one of these together with a covering letter to the TETRA manufacturer, and
files the other and a copy of the letter in the TEA2 File.
The TETRA manufacturer is responsible for passing (a copy of) the countersigned Confidentiality and Restricted Usage
Undertaking to the third party.
6.4 Third party operator supplying TETRA services with TEA2
NOTE: This clause covers the "supplier" licence type.
There may be a third party operator who is not a primary or secondary user, but who is supplying TETRA services with
TEA2 to primary and/or secondary users.
In this case, the third party operator has to sign two copies of the Confidentiality and Restricted Usage Undertaking for
Suppliers (see clause D) and sends these to the TEA2 Custodian.
The TEA2 Custodian then enters the transfer details in the TEA2 Register, countersigns the Confidentiality and
Restricted Usage Undertakings, returns one of these together with a covering letter to the third party operator, and files
the other and a copy of the letter in the TEA2 File.
ETSI

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11 ETSI TR 101 053-2 V2.2.2 (2008-09)
6.5 Use of TEA2 by a secondary user
NOTE: This clause covers the "user" licence type.
As described in clause 5.1 a military organization can become an approved recipient. Such a military organization is
referred to as a secondary user.
There are two cases:
1) There is a primary user in the home state or territory that is responsible for the public safety network
containing TEA2.
2) There is no such primary user in the home state or territory.
In the first case, the primary user has to ensure that the intended secondary user meets the approval criteria (i.e. fulfils
Approval Criterion C5 as in clause 7). The primary user has to get the intended secondary user to sign two copies of the
Confidentiality and Restricted Usage Undertaking for Users of TEA2 as in clause C. The primary user then sends these
to the TEA2 Custodian, at the same time indicating if the secondary user requires a copy of the TEA2 specification.
The TEA2 Custodian then enters the transfer details in the TEA2 Register, countersigns the Confidentiality and
Restricted Usage Undertakings, returns one of these to the primary user together with a covering letter and, if required,
a copy of the TEA2 specification and files the other and a copy of the letter in the TEA2 File. The primary user
transfers the Confidentiality and Restricted Usage Undertaking and, if applicable, the copy of the TEA2 specification to
the secondary user.
In the second case the secondary user has to demonstrate to the custodian written approval to operate a TETRA network
given by the governmental organization that is responsible for public safety in the home state or territory. The
secondary user signs two copies of the Confidentiality and Restricted Usage Undertaking for Users of TEA2 as in
clause C. The secondary user then sends these to the TEA2 Custodian, at the same time indicating if he requires a copy
of the TEA2 specification.
The TEA2 Custodian then enters the transfer details in the TEA2 Register, countersigns the Confidentiality and
Restricted Usage Undertakings, returns one of these together with a covering letter and, if required a copy of the TEA2
specification, to the secondary user, and files the other and a copy of the letter in the TEA2 File.
6.6 Distribution of TEA2 specification part 3 by the TEA2
custodian
The following procedures for distributing the TEA2 specification part 3 are defined:
1) The TEA2 Custodian receives a written request for one single copy of the TEA2 specification part 3.
2) The TEA2 Custodian sends one copy of the requested part 3 of the TEA2 specification part 3 to the applicant.
7 Approval criteria and restrictions
The approval criteria are set by the ETSI Project TETRA and maintained by the TEA2 Custodian. The TEA2 Custodian
may recommend changes to these criteria.
In order for an organization to be considered an approved recipient of TEA2 deliverables it has to satisfy at least one of
the following criteria:
C1 The organization is a bona fide designer or manufacturer of TETRA subscriber or fixed systems, where the
algorithm requested is included in the systems.
C2 The organization is a bona fide designer or manufacturer of components for TETRA subscriber or fixed
systems, where at least one of the components includes the algorithm requested.
C3 The organization is a bona fide designer or manufacturer of a TETRA system simulator for approval testing of
TETRA subscriber or fixed systems, where the simulator includes the algorithm requested.
ETSI

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