The trade-off between security and the existing IPX ... · The trade-off between security and the existing IPX business model ETSI Security Week | What does 5G security offer? Ewout

The trade-off between security and the existing IPX business model

ETSI Security Week | What does 5G security offer?Ewout Pronk KPN/Chair GSMA DESS group

© GSM Association 2018

Provides guidelines and requirements for end-to-end signalling security between LTE (4G) networks and between 5G networks

Serving the interest of mobile operators and their customers

Working closely together with 3GPP and other stakeholders in the ecosystem

Guide the implementation of a secure, yet flexible security solution

The work of the (Diameter) End-to-end Security Subgroup

2Security Classification: Non-confidential

The IPX network for LTE

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Trust

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The IPX network as described in GSMA documents

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Source: https://www.gsma.com/newsroom/wp-content/uploads/IR.88-v16.0-1.pdf

For routing purposes the IPX provider is the “one stop shop” for operators

Providing Quality of Service to both signalling and user plane messages

On top services are provided to operators:

– Mediation– Fraud control– Value Added Services

The need for IPX providers in the ecosystem

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Operators have a number of measures to protect themselves:– Apply topology hiding– Deploy a signalling firewall

But no measures exist to unambiguously determine authenticity and integrity of a Diameter signalling message end-to-end, and no encryption measures

Potentially leading to:– Denial of Service– Impersonation– Fraud– Tracking– Interception

So why not regulate the IPX providers and tell them what they should do?

The security implications of the hop-by-hop model

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The one who is responsible for the security (such as spoofing prevention) does not bear the cost/impact in case of a failure. In economics “An externality”

Economic effects hamper the effectiveness of regulation

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Assets

Regulation

LTE roaming operator 1 IPX provider B

DRA/DEA DRA/DEAGMLC

LTE roaming operator 2

MMEDRA/DEA

Mallory impersonating LTE roaming operator 1

GMLC

PL REQ

PL REQ

PL RESP

IPX provi der A

DRA/DEA

PL RESP

PL REQ

PL RESP

Regulation

The lack of end-to-end security has led to IPX providers to build services

Providing services is not only in the interest of IPX providers, many operators rely on them

And of course in general: the complexity of applying security measures to a fairly big ecosystem: key management, security awareness and resistance against mandatory measures

The complexity of providing end-to-end security

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Maximum flexibility Deviates from the goal to provide E2E security Paper tiger

against

Maximum security Jeopardizing the IPX business model

We are left with a difficult trade-off

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Thank you for your attention!

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