OVERVIEW OF PKM AUTHENTICATION MECHANISM IN WiMAX SECURITY PROTOCOL

OVERVIEW OF PKM AUTHENTICATION MECHANISM IN WiMAX SECURITY PROTOCOL

Zachariah Pabi GARIBA

MPhil Telecommunication Engineering 1

Graduate Student Member IEEE

Email: zpgariba.coe @st.knust.edu

KNUST

KNUST

PRESENTATION OUTLINE

IntroductionResearch ObjectivesWiMAX authentication protocolConclusionsReferences

KNUST

Mobile computingDefined as having access to computing resources from anywhere; one's ability to use computing technology whilst moving.

Since this system is design provides open access across vast networked environments, security issue becomes a difficult task as the mobile devices cannot be tracked down to a single location.

The vital goal of security solutions for mobile networks is to provide services such as authentication, confidentiality, integrity, anonymity and availability to mobile users.

security can be implemented in any of the OSI seven layers.

KNUST

Components of good security

Confidentiality: The non-occurrence of the unauthorized disclosure of information. No one except the sender and the receiver should have access to the information being exchanged.

Integrity: The non-occurrence of the unauthorized manipulation of information. No one except the sender and the receiver should be able to modify the information being exchanged.Authentication: The receiver’s ability to ascertain the origin of a message. An intruder should not be able to masquerade as someone else.Nonrepudiation: The receiver’s ability to prove that the sender did in fact send a given message. The sender should not be able to falsely deny later that he sent a message.

Service Reliability: The ability to protect the communication session against denial of service attacks.

KNUST

Component methods

Confidentiality: encryptionIntegrity: Message hash calculation

Authentication: Digital signature or challenge response schemesNonrepudiation: Time stamping

TUESDAY: 9TH FEBRUARY, 2010

KNUST

INTRODUCTION


Table 1: Security system requirement

KNUST

INTRODUCTION

Mobile computing devices

Laptop computers Personal Digital Assistants (PDAs) and handheld PCs PagersSmart phones and mobile phonesTask devices; bar code scan


KNUST

INTRODUCTION

Security componentsSecurity within networksSecurity for the devices

Supporting mobile computing networksTraditional wireless systemsWireless LANWireless Ad Hoc systems


KNUST

INTRODUCTION


Table 1: Security system requirement

KNUST

INTRODUCTION

WiMAX

The IEEE 802.16 protocol is also called WiMAX, which stands for worldwide interoperability of microwave access. It was first planned to offer the last mile for Wireless Metropolitan Area Network (WMAN) with the line of sight (LOS) of 30 – 50 km.

The original IEEE 802.16 standard covers line-of-sight connections in the 10–66GHz range, supporting speeds up to 280 Mbps over distances up to 50km (30 mi.). IEEE 802.16a covers non-line-of-sight connections in the 2–11GHz range, supporting speeds up to 75 Mbps over distances of 5–8km (3–5 mi.). IEEE 802.16a also adds features for mesh networks, while the 802.16e standard adds support for mobility.


KNUST TUESDAY: 9TH FEBRUARY, 2010

Table 2 IEEE 802.16 standard evolution

KNUST

RESEARCH OBJECTIVES

To thoroughly review the authentication aspects of IEEE 802.16 standardTo underscore the security vulnerabilities and threats associated with WiMAX authentication.

KNUST

RESEARCH METHODS

The research approaches will include qualitative and quantitative research methods, and computer simulation.

Present published security issues of IEEE 802.16 protocol in journals and conferences shall be review and the further readings for proposed security improvement.

KNUST

IEEE 802.16 SECURITY PROTOCOL

Transmission convergence sublayer

QPSK 16QAM 64QAM 256QAM

Security sublayer (PS)

Common part sublayer (CPS)

Convergence sublayer (CS)

Link layer control (LLC)

PHY Layer (L1)

MAC (L2)

Fig. 1: IEEE 802.16 protocol stack

KNUST


The protocol architecture

The security sublayer has two protocols as follows;An encapsulation protocol for securing packet data across the BWA network.A key management protocol (PKM) providing the secure distribution of keying data from the BS to the SS.

KNUST

Fig. 2: WiMAX security sublayer

KNUST


Privacy and key management (PKM)

SS uses PKM to obtain authentication and traffic keying from BS

PKM has two categoriesSS authorization and AK exchangeTEK exchange

KNUST


Key management protocolThe PKM protocol allows for both mutual authentication and unilateral authentication. It also supports periodic reauthentication/reauthorization and key refresh.

The key management protocol uses either EAP or X.509 digital certificates together with RSA public-key encryption algorithm.

There are two Key Management Protocols supported in this standard: PKM version 1 and PKMv2 with more enhanced features such as new key hierarchy, AES-CMAC, AES key wraps, and MBS.

KNUST


Authentication

Hash Message Authentication Code (HMAC)X.509 certificate

Manufacture certificateSubscriber certificateBase station certificate

Extensible Authentication Protocol (EAP)

IEEE 802.16-2004

KNUST


Authentication protocols

PKM supports two distinct authentication protocol mechanisms:RSA protocolExtensible Authentication Protocol (optional)

An SS uses the PKM protocol to obtain authorization and traffic keying material from the BS, and to support periodic reauthorization and key refresh.

KNUST


PKM RSA authentication

The PKM RSA authentication protocol uses X.509 digital certificates the RSA public key encryption algorithm that binds public RSA encryption keys to MAC addresses of SSs.

All RSA authentication have factory-installed RSA private/public key pairs or provide an internal algorithm to generate such key pairs dynamically.

KNUST


PKM EAP authentication

PKM EAP Authentication uses Extensible Authentication Protocol in conjunction with an operator-selected EAP Method (e.g. EAP-TLS).

The EAP method uses credentials such as an X.509 certificate in the case of EAP-TLS or a Subscriber Identity Module in the case of EAP-SIM.

KNUST


KNUST

IEEE 802.16 SECURITY

PKM v1

SS authorization and AK exchange overview: SS authorization, controlled by the Authorization state machine, is the process of the BS authenticating a client SS’s identityAuthorization via RSA authentication protocol: SS begins authorization by sending an Authentication Information message to its BS. The Authentication Information message contains the SS manufacturer’s X.509 certificate.

KNUST


PKMv2

I.The PKMv2 key hierarchy defines what keys are present in the system and how the keys are generated. Since there are two authentication schemes, RSA and EAP, there are two primary sources of keying material.II.The RSA-based authorization process yields the pre-Primary AK (pre-PAK) and the EAP based authentication process yields the MSK.III.All PKMv2 key derivations are based on the Dot16KDF algorithm: The Dot16KDF algorithm is a counter mode encryption (CTR) construction that may be used to derive an arbitrary amount of secret key from source keying material.

KNUST


Digital signatures

Manufacture certificatesSS certificateBS certificate

KNUST


Cryptographic methods In PKMv2, SAs using a cipher suite employing DES-CBC, the TEK in the Key Reply is triple DES (3-DES) encrypted, using a two-key, 3-DES KEK derived from the AK.

The lifetimes of the two generations overlap such that each generation becomes active halfway through the life of it predecessor and expires halfway through the life of its successor.

KNUST

Fig. 4: WiMAX security procedure

KNUST


Fig. 6: WiMAX overview

KNUST


Threats and vulnerabilities

Threats in the IEEE 802.16 standards have been grouped into two;

Physical layer threats and vulnerabilitiesMAC layer threats and vulnerabilities

KNUST


Physical layer threats

Jamming and scrambling attacksWater torture attackReplay attacks in IEEE 802.16e mesh modes

KNUST


ThreatsMAC management messages are sent in plain-text and not cipher-text.X.509 digital certificate; it uses RSA encryption with SHA-1 hashing.Downgrade attack is possible on the initial TEK authentication. The security capabilities are sent by SS to BS over an insecure connection, before negotiating the encryption keys, these include the kind of crypto functions to be used to cipher the data packets.In IEEE 802.16e SS can authenticate with BS with the new PKMv2 RSA authentication with its public key. Public key encryption and signature is a computationally heavy operation, so if flooded with false requests, the BS may be victim of a denial of service attack, using all its resources to evaluate digital signatures.

KNUST

CONCLUSIONS

In mesh mode, an insider attacker can fool other nodes of the mesh to create man in the middle attacks, invade their privacy.There has been PKMv2 in the amended 2004 version which uses more enhanced features such as new key hierarchy, AES-CMAC, AES-key-wraps, and MBS.There is of BS X.509 digital certificate in IEEE 802.16eThe standard security mechanism does not handle layer 1 security.Potential security flaws also exist in IEEE 802.16e, especially the flaw existing in subscriber handover procedure.IEEE 802.16 supports mesh modeThere has been little research on layer 1 security issues for IEEE 802.16/WiMAX.

KNUST

REFERENCES[1] Ahson, S. and Ilyas, M. (2008), WiMAX Standards and Security, CRC Press, Boca Raton, pp. 19-55, 197-243.[2] IEEE (2009), IEEE Standard for Local and metropolitan area networks: Air Interface for Broadband Wireless Access Systems (IEEE Std 802.16™-2009), IEEE, New York, pp. 558-565.[3] Menezes, A. Oorschot, P. V. and Vanstone, S. (1997), Handbook of Applied Cryptography, CRC Press, Boca Raton, pp. 1-42.[4] Di, P. et al. (2007), 'Overview and Analysis of IEEE 802.16e Security'.[5] Xu, S. and Huang, C.-T. (2008), 'Attacks on PKM Protocols of IEEE 802.16 and Its Later Versions'.[6] Deininger, A. et al. (2007), 'Security Vulnerabilities and Solutions in Mobile WiMAX', IJCSNS International Journal of Computer Science and Network Security, vol. 7, no. 11, pp. 7-17.[7] Xu, S. Matthews, M. and Huang, C. (2006), 'Security Issues in Privacy and Key Management Protocols of IEEE 802.16', http://www.cse.sc.edu/~huangct/acmse06cr.pdf, [30th August 2009 at 00: 57].[8] Barbeau, M. (2008), 'WiMAX/802.16 Security in Mesh Mode', pp. 1-11.[9] Maccari, L. Paoli, M. and Fantacci, R. (2007), 'Security analysis of IEEE 802.16', ICC 2007.

http://www.cse.sc.edu/~huangct/acmse06cr.pdf

KNUST

THE END

OVERVIEW OF PKM AUTHENTICATION MECHANISM IN WiMAX SECURITY PROTOCOL

Education

wimax security sublayer

networks security

security protocol authenticati

security protocolprivacy

security vulnerabilities

pkm protocol

authentication aspects

standard evolution knust