5G-ENSURE Security Architecture

Alireza Ranjbar, Ericsson

Ghada Arfaoui, Orange

ETSI security week, 16th June 2017

5G Security Architecture - Overview

A security architecture provides a high level overview of

involved entities,

its interactions and,

the trust relationships between them.

Enhance security, privacy and resilience.

Main idea: Extend 3GPP security architectures of 3G/4G to capture new technologies, use cases, trust models and features of 5G networks.

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Limitations in 4G Architecture (TS 33.401)

Two main concepts: Domain and Stratum.

Like to build on proven concepts but…

Trust relations are not reflected

Relevant 5G use cases and business models are not captured.

Technical issues:

Management aspect is omitted.

Service delivery models (i.e., Virtualization and Network slicing concepts) are not visible.

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Home

stratum/ Serving

Stratum

Transport stratum

ME

Application

stratum User Application Provider Application

(IV)

(III)

(II)

(I)

(I)

(I)

(I)

(I)

SN

AN

(I)

USIM

(II)

HE

Domains (TS 23.101)

Domain: The highest-level group of physical entities. Reference points are defined between domains.

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User Equipment Domain

Access Network Domain

Core Network Domain

Infrastructure Domain

Cu

Mobile Equipment Domain

USIM Domain

Home Network Domain

Transit Network Domain

Uu Iu

[Zu]

[Yu]

Serving Network Domain

In 5G, may have several Infrastructure domains from different providers,

Better starting point for modelling trust! But some gaps….

Slicing?

Virtualization?

Management?

Stratum (TS23.101)

A stratum is a grouping of protocols related to one aspect of the services provided by one or several domains.

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USIM

MT - AN

MT/ME Access Network Domain

Serving Network Domain

Home Network Domain

AN - SN

“Access Stratum”

MT - SN

“Serving Stratum”

USIM - HN

SN - HN

“Home Stratum”

MT - SN USIM - MT

“Transport Stratum”

USIM - MT

TE

MT - AN

MT

Access Network Domain

Serving Network Domain

Transit Network Domain

AN - SN

“Access Stratum”

TE - MT MT - SN

“Serving Stratum”

Application Stratum

Application

“Transport Stratum”

Remote Party

Mobile Equipment

Domain

Management?

5G domains and strata - Definitions

A domain is a grouping of network entities according to physical or logical aspects that are relevant for 5G networks.

A Compound domain is a collection of other domains, grouped together according to some 5G relevant aspect, e.g. ownership, joint administration.”

A stratum is a grouping of protocols, data, and functions related to one aspect of the services provided by one or several domains.

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Management domain

Management domain(s)

Management domain(s)

Management domain

5G (Security) Domains

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Other UE domains

Core network domain

Access network domain

User equipment domain

TN domain

Operator network domain

3P domain

USIM domain ME domain

HN domain

IM domain

IPS domain

External network domain

Network domain

TA Trust Anchor(s)

IP Domain

IP domain

TA

IP domain MEHW domain UICC domain

IP domain

TA

IP domain

TA TA TA

TA

IP domain IP Domain IP domain

TA

TA

SN domain Access domain RAT 1

Access domain RAT 2

Slice Domain(s)

SD

SD

SD

SD

SD

SD

SD SD

SD

SD

SD

Management domain

Management domain(s)

Management domain(s)

Management domain

5G Security Domains – ETSI

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Other UE domains

Core network domain

Access network domain

User equipment domain

TN domain

Operator network domain

3P domain

USIM domain ME domain

HN domain

IM domain

IPS domain

ETSI

Ten

ant

do

mai

ns

ETSI

Infr

astr

uct

ure

d

om

ain

s

External network domain

Network domain

TA Trust Anchor(s)

IP Domain

IP domain

TA

IP domain MEHW domain UICC domain

IP domain

TA

IP domain

TA TA TA

TA

IP domain IP Domain IP domain

TA

TA

SN domain Access domain RAT 1

Access domain RAT 2

Slice Domain(s)

SD

SD

SD

SD

SD

SD

SD SD

SD

SD

SD

ETSI Administrative domain

5G Strata

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Transport

Serving

Application

Home

Access

Security Feature Groups (TS 33.401)

TS 33.401 defines Network access security (I) Network domain security (II) User domain security (III) Application domain security (IV) Visibility and configurability of security (V)

These are unclearly motivated/defined E.g. “user domain” basically just comprises the PIN access code to the UICC

Replace by Security Realms, Security Control Classes

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Home

stratum/ Serving

Stratum

Transport stratum

ME

Application

stratum User Application Provider Application

(IV)

(III)

(II)

(I)

(I)

(I)

(I)

(I)

SN

AN

(I)

USIM

(II)

HE

Security Realms

A Security Realm (SR) captures security needs of one or more strata or domain(s).

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Security Realm Note Access Network Security Corresponds closely to “Network Access

Security” Feature Group of 33.401

Application Security Corresponds closely to “Application Security” Feature Group of 33.401

UE Security

Very loosely related to “User Security” SFG of 33.401

Network Security Corresponds somewhat to “Network Security” Feature Group of 33.401

Management Security No counterpart in 33.401

Infrastructure & Virtualization Security No counterpart in 33.401

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Security Control Classes

A Security Control Class (SCC) is a collection of security functions (including safeguards and countermeasures) to avoid, detect, counteract, or minimize security risks to 5G networks, in particular, risks to a network’s physical and logical infrastructure, its services, the user equipment, signalling, and data. An extension of the well-known CIA-triad

Confidentiality Integrity Availability

Used in many contexts ISO 27001, IETF, NIST, SANS, CSA We define 10 Security Control Classes.

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SR & SCC Matrix

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Security Realms

Security Control Classes ID & Access Mgmt

AuthN Non-repudiation

Confid. Integrity Availability Privacy Audit Trust & Assurance

Compliance

Access Network Security

Application Security

UE Security

Network Security

Management Security

Infra.& Virtualiz. Security

Intend to map threats T into this matrix (i.e. “threat to confidentiality in App. Realm”) For each threat, a corresponding requirement R should be in place.

T R

Summary

Our high-level security architecture re-uses well-known concepts, extending to 5G security landscape is described in terms of

Domains & Strata Security Realms & Security Control Classes

Allows to map our trust model and enablers.

For more info, see our Deliverable D2.4, http://5gensure.eu/sites/default/files/Deliverables/5G-ENSURE_D2.4-SecurityArchitectureDraft.pdf

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This research has been performed within 5G-ENSURE project (www.5GEnsure.eu) and received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 671562.