ETSI TR 104 291 V1.1.1 (2026-04)

TETRA and Critical Communications Evolution (TCCE); TETRA security; Additional security measures introduced in TETRA standards

DTR/TCCE-06228

General Information

• Status: Not Published
• Technical Committee: TCCE 6 - TCCE Security
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Due Date: 18-Apr-2026
• Completion Date: 20-Apr-2026

Standards Content (Sample)

TECHNICAL REPORT
TETRA and Critical Communications Evolution (TCCE);
TETRA security;
Additional security measures introduced in TETRA standards

2 ETSI TR 104 291 V1.1.1 (2026-04)

Reference
DTR/TCCE-06228
Keywords
security, TETRA
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3 ETSI TR 104 291 V1.1.1 (2026-04)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 4
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 6
3.1 Terms . 6
3.2 Symbols . 7
3.3 Abbreviations . 7
4 Security enhancements . 7
4.1 New authentication and air interface encryption algorithms . 7
4.1.1 Threat . 7
4.1.2 Countermeasure . 8
4.2 Requirement for different RAND values . 8
4.2.1 Threat . 8
4.2.2 Countermeasure . 8
4.3 TDMA frame number validation - uplink . 8
4.3.1 Threat . 8
4.3.2 Countermeasure . 9
4.4 TDMA frame number validation - downlink . 9
4.4.1 Threat . 9
4.4.2 Countermeasure . 9
4.5 Entropy of TEA1 . 9
4.5.1 Threat . 9
4.5.2 Countermeasure . 9
4.6 Identity Encryption . 9
4.6.1 Threat . 9
4.6.2 Countermeasure . 10
4.7 Message injection . 10
4.7.1 Threat . 10
4.7.2 Countermeasure . 10
4.8 Reuse of CCK between algorithms . 10
4.8.1 Threat . 10
4.8.2 Countermeasure . 10
4.9 End-to-end encryption . 11
History . 12

ETSI
4 ETSI TR 104 291 V1.1.1 (2026-04)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are 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 IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
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.
Trademarks
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3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee TETRA and Critical Communications
Evolution (TCCE).
Modal verbs terminology
In the present document "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be
interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
TETRA security is specified in ETSI EN 300 392-7 and ETSI TS 100 392-7 [i.1] (latest version of either specification
applies) for Trunked Mode Operation (TMO) and in ETSI EN 300 396-6 and ETSI TS 100 392-6 [i.2] (latest version of
either specification applies) for Direct Mode Operation (DMO). The security mechanisms specified in these documents
have evolved over time in response to changing market needs and to perceived vulnerabilities.
Version 4.1.1 of [i.1] and version 2.1.1 of [i.2] incorporated new authentication algorithms ([i.1] only) and air interface
encryption algorithms ([i.1] and [i.2]) to ensure that TETRA security remains protected against brute force attacks into
the future as the cost of computing power falls over time. During development of these specifications, perceived
vulnerabilities in the previous versions of these specifications were published, and so the revised specifications also
include countermeasures against these perceived vulnerabilities. The perceived vulnerabilities were declared to ETSI
under the ETSI CVD (Coordinated Vulnerability Disclosure) process, and all finders of perceived vulnerabilities are
encouraged to use this process. ETSI TCCE have now also defined a TETRA-specific policy document which adds
TCCE-specific roles and responsibilities to the ETSI process (ETSI TR 104 246 [i.3]).
ETSI
5 ETSI TR 104 291 V1.1.1 (2026-04)
The purpose of the present document is to list the updated security measures included in [i.1] from version 4.1.1
onwards and [i.2] from version 2.1.1 onwards, and the threats (or perceived vulnerabilities) against which the updates
were made. This should allow users of TETRA to make their own evaluation of the threats, and to decide the necessity
or urgency for implementing the countermeasures that were added to the standards in their own TETRA systems.

ETSI
6 ETSI TR 104 291 V1.1.1 (2026-04)
1 Scope
The present document describes the additional security measures put in place in the TETRA security standards, ETSI
TS 100 392-7 [i.1] version 4.1.1 and later, and ETSI TS 100 396-6 [i.2] version 2.1.1 and later.
Clause 4 describes the security measures in turn, and the threats that led to the inclusion of each of measures. The
threats may be due to a change in environment, or to specific perceived vulnerabilities in the TETRA standard. Clause 4
also lists countermeasures and, where applicable, the clauses in [i.1] in which they are specified.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For spe
...