LTE Security

Dan Forsberg, Poplatek Oy, Finland Dr. Dan Forsberg is currently a development manager at Poplatek Oy where he takes care of the payment terminals area and also works with payment card industry security. Earlier, Dan led the SAE/LTE security standardization work in Nokia. He was also nominated as one of the Nokia top inventors in 2007-2008. Dan started his Ph.D. studies while working in Nokia and has published several scientific papers in the area of "improving and distributing session key management for mobile networks". He joined Helsinki University of Technology in 2009 and finalized his PhD studies there before the end of 2009. Gnther Horn, Nokia Siemens Networks, Germany Dr Horn is a senior standardization expert at Nokia Siemens Networks. The focus of his work is on the standardization of 3G and SAE/LTE security in the 3GPPP security group (SA3), of which he has been a member since it started in 1999. Wolf-Dietrich Moeller, Nokia Siemens Networks, Germany Wolf-Dietrich Moeller is a senior researcher with Nokia Siemens Networks. Valtteri Niemi, University of Turku, Finland and Nokia Corporation, Finland Dr Niemi is a Professor of Mathematics in University of Turku, Finland and also a Nokia Fellow, for which role he is based at the Nokia Research Center in Helsinki, Finland. Prof. Niemis work has been on security and privacy issues of future mobile networks and terminals, the main emphasis being on cryptological aspects. He participated in the 3GPP SA3 (security) standardization group from the beginning, and during 2003-2009 he was the chairman of the group.

Preface xiii Foreword to the First Edition xv Acknowledgements xix Copyright Acknowledgements xix 1 Overview of the Book 1 2 Background 5 2.1 Evolution of Cellular Systems 5 2.2 Basic Security Concepts 10 2.3 Basic Cryptographic Concepts 13 2.4 Introduction to LTE Standardization 21 2.5 Notes on Terminology and Specification Language 26 3 GSM Security 29 3.1 Principles of GSM Security 29 3.2 The Role of the SIM 30 3.3 Mechanisms of GSM Security 31 3.4 GSM Cryptographic Algorithms 34 4 Third-Generation Security (UMTS) 37 4.1 Principles of Third-Generation (3G) Security 37 4.2 Third-Generation Security Mechanisms 40 4.3 Third-Generation Cryptographic Algorithms 49 4.4 Interworking between GSM and 3G Security 55 4.5 Network Domain Security 59 4.6 Architectures with RNCs in Exposed Locations 65 5 3GWLAN Interworking 67 5.1 Principles of 3GWLAN Interworking 67 5.2 Security Mechanisms of 3GWLAN Interworking 75 5.3 Cryptographic Algorithms for 3GWLAN Interworking 81 6 EPS Security Architecture 83 6.1 Overview and Relevant Specifications 83 6.2 Requirements and Features of EPS Security 89 6.3 Design Decisions for EPS Security 97 6.4 Platform Security for Base Stations 103 7 EPS Authentication and Key Agreement 109 7.1 Identification 109 7.2 The EPS Authentication and Key Agreement Procedure 112 7.3 Key Hierarchy 123 7.4 Security Contexts 129 8 EPS Protection for Signalling and User Data 133 8.1 Security Algorithms Negotiation 133 8.2 NAS Signalling Protection 136 8.3 AS Signalling and User Data Protection 138 8.4 Security on Network Interfaces 141 8.5 Certificate Enrolment for Base Stations 143 8.6 Emergency Call Handling 151 9 Security in Intra-LTE State Transitions and Mobility 155 9.1 Transitions to and from Registered State 156 9.2 Transitions between Idle and Connected States 157 9.3 Idle State Mobility 158 9.4 Handover 161 9.5 Key Change on the Fly 169 9.6 Periodic Local Authentication Procedure 170 9.7 Concurrent Run of Security Procedures 171 10 EPS Cryptographic Algorithms 175 10.1 Null Algorithms 176 10.2 Ciphering Algorithms 177 10.3 Integrity Algorithms 180 10.4 Key Derivation Algorithms 180 11 Interworking Security between EPS and Other Systems 183 11.1 Interworking with GSM and 3G Networks 183 11.2 Interworking with Non-3GPP Networks 193 12 Security for Voice over LTE 215 12.1 Methods for Providing Voice over LTE 215 12.2 Security Mechanisms for Voice over LTE 220 12.3 Rich Communication Suite and Voice over LTE 230 13 Security for Home Base Station Deployment 233 13.1 Security Architecture, Threats and Requirements 234 13.2 Security Features 241 13.3 Security Procedures Internal to the Home Base Station 244 13.4 Security Procedures between Home Base Station and Security Gateway 247 13.5 Security Aspects of Home Base Station Management 261 13.6 Closed Subscriber Groups and Emergency Call Handling 275 13.7 Support for Subscriber Mobility 277 14 Relay Node Security 281 14.1 Overview of Relay Node Architecture 281 14.2 Security Solution 284 15 Security for Machine-Type Communications 293 15.1 Security for MTC at the Application Level 294 15.2 Security for MTC at the 3GPP Network Level 301 15.3 Security for MTC at the Credential Management Level 306 16 Future Challenges 309 16.1 Near-Term Outlook 309 16.2 Far-Term Outlook 314 Abbreviations 319 References 327 Index 337