Incorporating privacy into security standardization - … privacy into security standardization ... •Use of dynamic or pseudonymous identifiers –GSM & successors, ... addresses

4th ETSI Security Workshop January 2009

Copyright © 2009 Intel Corporation. All rights reserved. 1

Incorporating privacy into security standardization

13 January 2009

Claire Vishik, Intel UK

4th ETSI Security Workshop, January 2009


Summary

• Introduction: technology & security trends, security & privacy, standards landscape

• Building privacy friendly standards

• Examples: privacy as a necessary component of accepted security technologies– Mobile telephony: GSM

– Networks (IPv6)

– Services: authentication, delegation

– Hardware: Trusted Computing

• Conclusions

• Questions & Discussion



Purpose

• Explain that privacy is a complex set of requirements that permeates all aspects of electronic communications, data, and services and is necessary for the acceptance of new technologies

• Touch upon some of the methods used to ensure privacy-friendly features in security & adjacent standards



Introduction

• Technology trends, relationship between privacy & security, relevant standards’ landscape



Some Technology Trends

• Increasing mobility

• Ubiquitous connectivity

• Increasing computing power of diverse devices

• Different level of security & privacy protection of various devices & networks involved in the same set of activities

• Global digital economy



Today’s interconnected environment & data exchanges

A very large number of identifiers pass through networks and backend/client systems

E-commerce systemsPlatform IDs

Mobile Commerce: Transfer of identifiers

Passes through a WAP Gateway (TCP/IP Translation)

3

1An e-commerce transaction starts on a phone (Phone & Subscriber IDs)

4

HeterogeneousNetworks

X

Is transmitted through wireless and wireline network2

Wireline log(wire IDs)

Wireless context(Wireless ID’s)

Moves to TCP/IP networks andbackend systems (user and system IDs)



Communications, Services

Content

Internet

Commerce

FTP, SSHWeb Services/SOAP

HTTPAS1, AS2, AS3,

SSL/TLSS/MIME

Internal Business Units

Internal Business Units

Internal Business UnitsBack-end

Massive Standardization Efforts

Web Services/SOAP

HTTP

SSL/TLS

XML

SAML

Directory

Web Services/SOAP

HTTP, XML, RSS

Many standards are an integral part of today’s computing environment

and require security & privacy support

Many standards are an integral part of todayMany standards are an integral part of today’’s computing environments computing environment

and require security & privacy supportand require security & privacy support

IPv6/IPv4

Wi-Fi Wimax

GSM, 3G, 4F

Trusted Computing



Core Technologies & Standards: “Group” Effort

Protect Client

Devices

Protect Back-

end Systems

Protect

Networks

Protect Users

Ensure

Privacy

•Secure OS, virtualization•Hardware security & Trusted Comp• “Protection” software

•Anonymity•Verification, not identification•Strict privacy policies•Privacy-friendly design

•Authentication• Firewalls, IDS, extrusion detection systems• Increase resilience•Response and remediation

• Identity management•Strong authentication•Training•Usability

•OS Hardening, virtualization•Hardware security•Transport encryption•Encryption for data at rest

TCG, OASIS, IETF, UEFI,

others

W3C, OASIS, TCG, IETF, IEEE

IEFT, OASIS, ETSI, ITU-T

OASIS, Liberty Alliance, IEEE

W3C, JTC1

GoalGoal ApproachesApproaches StdsStds BodiesBodiesKey PlayersKey PlayersOEMs, components &

OS vendors, researchers,

“protection” tools vendorsISVs

Hardware, OS,

security/encryption,

database, integration

vendors, researchers

Network equipment, Telecoms, firewalls, IDC vendors, CERTs

Authentication, OS &hardware vendors,

OEMs, ISPs, researchers,

regulators

All key players, researchers, ISVs,

regulators



Definitions; Some Methods Used to Implement Privacy Friendly Features



Privacy/Privacy Enhancing Technologies

• What information is relevant to privacy?

– “any information relating to an identified or identifiable natural person […]; an identifiable person is one who can be identified, directly or indirectly, in particular by reference to an identification number or to one or more factors specific to his physical, physiological, mental, economic, cultural or social identity” (EU Directive 95/46/EC, Art. 2 (a)).

• Some privacy-enhancing approaches:

– Anonymity (or pseudonymity) –disconnection from PII

– Unlinkability –cannot be easily linked to PII

– Avoidance of re-identification (subjects or their devices cannot be re-identified with the assistance of other datasets

– Support for confidentiality

• Other privacy requirements:

– Notice & choice

OECD Privacy Guidelines (1980)

• Openness• Data quality principle• Purpose specification principle• Use limitation principle• Security safeguards principle• Openness principle• Individual participation• Accountability



Privacy, Security, Interoperability & Trust

Establishment

• In trusted environments, more information is disclosed & shared

– Enhanced privacy requirements may apply

• In high security environments, incomplete disclosure may not be permitted

– Privacy requirements may be different

• Interoperability among systems and networks make it imperative to provide information about networks, devices, and users

– Higher level approaches to privacy are required



Some Methods to Enhance Privacy

• Use of dynamic or pseudonymous identifiers – GSM & successors, DHCP, IPv6

• Unlink cryptographic keys and credentials, to limit cryptographic associations between identifiers– TPM1.2 & ISO/IEC equivalent

• Substitute complete disclosure (identification) with positive verification– Research projects

• Protect data in transit and at rest– Wi-Fi, WiMax, secure application protocols, many other examples



Some examples

• DHCP, IPv6 (IETF)

• GSM (ETSI)

• Trusted Computing (TCG)

• Services: SAML (OASIS)

• Pre-standards research: verification versus identification (Prime, PrimeLife; Open TC)

• Data encryption examples are not included as this approach is very common

• These are representative examples; many more are available



DHCP Address –Dynamic/Pseudonymous ID

• Dynamic IP addresses– Assigned by a DHCP (Dynamic Host Configuration) server; change according to policy.

– Same structure as static IP addresses

• Implementation weakness: in many situations, DHCP addresses do not have to be actively re-rented– DHCP address may last as long as the device (PC or router) remains on• In this case, DHCP provides limited privacy protection



IPv6 Privacy: Dynamic Identification

• Privacy extensions for stateless address configuration

– Nodes use stateless auto-configuration to generate addresses combining network prefixes and interface identifiers. Static IDs (e.g. MAC addresses) are substituted with derivations

– Addresses change over time, making it harder to re-identify devices involved in transactions



Mobile Phone IDs (GSM):

Dynamic/Pseudonymous ID• Equipment

– GSM, e.g., uses 15 digit International Mobile Equipment Identity (IMEI) number (e.g. 35-209900-176148-1 ) embedded by manufacturer

– IMEI is used for processing or blocking phone connections• Identifies device only.

• Subscriber– SIM card has IMSI (International Mobile Subscriber Identifier)– Used for carrying-out subscriber-specific services

• IMSI is also stored in HLR (Home Location Register) file on the network

• Used for subscriber identification

– Real IMSI is sent as rarely as possible, and is substituted with randomly generated TMSI (temporary parameter)

• IMEI and IMSI together are used to enable security features in mobile networks



TPM Objects & Key Hierarchy: Unlinking the Keys

Dynam

ically

Lo

aded

Pers

iste

ntly S

tore

d

Endorsement Key

Storage Root Key

AttributesOwner

Migratable

Storage Key

Migratable

Protected

Data

Migratable

Signing Key

Non-Migratable

Storage Key

Migratable

Storage Key

Non-Migratable

Signing Key

Non-Migratable

Protected Data

Attestation ID

Key

No direct or cryptographic association between EK and AIK



SAML – pseudonymous IDs, varying levels of disclosure, encryption of

confidential components

• Standard Assertion Markup Language

– Authentication, single sign-on

• Privacy friendly features in v.2.0

– Support for pseudonyms and pseudonymous Id managements

– Metadata supports variable level of disclosure of trust data

– Components or complete assertions may be encrypted

– Mechanisms permitting porviders to communicate privacy policy



Minimal Disclosure Work: Pre-Standard

• Frequently, it is not important to identify an individual or device, but rather to verify the current status of the authorization

– E.g., ability to use some Internet services (13 or older), ability to access internal networks (authorized device in good standing), attestation request/reply

• Examples:

– Direct Anonymous Attestation protocol in TCG

– Property based attestation work (several institutions)

– Zero-sum & group signature authentication (Prime, PrimeLife)



Conclusions

Main points, future directions



AlwaysAlways consider privacy requirements for security/related standardsconsider privacy requirements for security/related standards

Use Use a varietya variety of available technologiesof available technologies to ensure privacy to ensure privacy

Compensate for older standards lacking privacy protectionCompensate for older standards lacking privacy protection

Adopt Adopt comprehensive comprehensive approach matching todayapproach matching today’’s computing environments computing environment

Weak authentication & ID systemsWeak authentication & ID systems

Level of Level of

AdoptionAdoptionIssueIssue

Use a combination of approaches to ensure the best coverage for privacy features

Privacy as a Necessary Part of Security & Other Standards

Common New



Questions?

Thank you!



Documents

Incorporating privacy into security standardization - … privacy into security standardization ... •Use of dynamic or pseudonymous identifiers –GSM & successors, ... addresses