doc.: IEEE 802.11-12/0041r1

Submission

Name Affiliations Address Phone emailRobert Sun; Yunbo Li;

Edward Au; Phillip Barber

Huawei Technologies Co., Ltd.

Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1

+1 613 2871948 Rob.sun@huawei.com

Performance Analysis of 802.11 authentication and authorization

• Date: 2011-11-15

Slide 1

Authors:

Rob Sun etc, Huawei.

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission Slide 2

Abstract

Rob Sun etc, Huawei.

• This proposal provides analysis of primary delay contributors within RSNA security protocol in accordance with IEEE 802.11i.

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Conformance w/ TGai PAR & 5C

Rob Sun etc, Huawei.Slide 3

Conformance Question Response

Does the proposal degrade the security offered by Robust Security Network Association (RSNA) already defined in 802.11?

No

Does the proposal change the MAC SAP interface? No

Does the proposal require or introduce a change to the 802.1 architecture? No

Does the proposal introduce a change in the channel access mechanism? No

Does the proposal introduce a change in the PHY? No

Which of the following link set-up phases is addressed by the proposal?(1) AP Discovery (2) Network Discovery (3) Link (re-)establishment / exchange of security related messages (4) Higher layer aspects, e.g. IP address assignment

3

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

IEEE 802.11 EAP Authentication and Authorization

Delay Contributors

• EAP Authentication Phases– EAPOL handshake

– EAP specific methods Authentication and Key establishment• Key Agreement

• Key Generation

• Key Transport

– 4-Way handshake

Rob Sun etc, Huawei.Slide 4

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

.11 EAPOL Handshake

Purpose: To initiate the EAP/802.1X based authentication;

Components: - EAPOL Start (STA ->AP)

- EAPOL Identity Request (AP ->STA)

- EAPOL Identity Response (STA ->AP)

- EAPOL success/failure (AP ->STA)

Primary Delay Contributors T1:

- air time transmission

Rob Sun etc, Huawei.Slide 5

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission Rob Sun etc, Huawei.Slide 6

DIFS CW Preamble Data SIFS Preamble Data

Message Frame ACK Frame

SIFS = 16 us;DIFS = 34 us;CW = 67.5 us; (average of CWmin);Preamble:= L-STF (8us)+L-LTF(8us)+L-SIG(4us)+HT-SIG(8us)+HT-STF(4us)+HT-LTF(4us) = 36 us;

Data rate = 6.5 Mbps; (MCS0 in 802.11n)

Results:• EAPOL start air time = 369.1us• EAPOL identity request = 369.1us• EAPOL identity response = 1476.8 us• EAPOL success =369.1us

• Total T1= 2584 us =2.5ms Reference: •Draft P802.11REVmb_D12.0

Air Time of 802.1X EAPOL messages

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

EAP Authentication and Key establishment

• Purpose : To provide the mutual authentication and RSNA key establishment• Components : EAP Specific Authentication

- Different EAP methods are examined for delay comparison

Hypothesis : PSK based EAP methods consumes less key establishment time than X.509 certificate based pair-wise key establishment ( reference: RFC 5216, and FIPS SP 800 56A)

. Primary Delay Contributor T2:

- X.509 certificate verification delay

- Key generation delay

- Handshake Delay (Air time + Wired Delay) Note1: All EAP methods are assumed using minimum 4 message handshake as per RFC 5216

Note 2: Wired Delay is non negligible but wasn’t calculated

Rob Sun etc, Huawei.Slide 7

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Performance of various EAP methods and EAP-PSK methods

• Testing Environment:

Server and Client Side:– CPU: PIII 550Mhz

– RAM: 256M

– OS: Windows XP

– HD: 40G

– Simulation Software: OpenSSL (Open source toolkit for TLS)

– # of Iterations: 100,000

Rob Sun etc, Huawei.Slide 8

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Client and Server processing time• Both Client and Server processing time including the following operations

– Initialization

– Key Processing

– Signature Processing

• Tested Candidates:

1) EAP-PSK (RFC 4764)

2) EAP-TLS w/ cipher suites of DHE-DSS-1024

3) EAP-TLS w/ cipher suites of RSA 1024 (PKCS #1)

– For DHE-DSS-1024 with mutual authentication

– For RSA 1024 with server authentication

Rob Sun etc, Huawei.Slide 9

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Client and Server processing time

Rob Sun etc, Huawei.Slide 10

EAP Methods Client Processing time (ms) Server Processing Time (ms)

EAP-PSK 4.83375 4.83375

EAP-TLS (DHE-DSS-1024) 198.8564 198.8564

EAP-TLS (RSA-1024) 9.869796 27.568796

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

4-Way Handshake Processing Time

• Purpose: To establish the trust and derive the over-the-air session keys between STA and AP

• Component: – Initialization (Nonce generation)

– MIC calculation

– KDF function

– 4 EAPOL key messages

• Primary delay contributors T3: - KDF function

- Handshake air time Note: same testing environment

Rob Sun etc, Huawei.Slide 11

4 WAY handshake Processing Time (ms) Initialization 0.635518 KDF functions and MIC 5.03574 Air time 1.22 Total 6.891258

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doc.: IEEE 802.11-12/0041r1

Submission

Conclusion• Total Time consumed by RSNA authentication and key establishment is:

• 802.1X EAPOL over the air handshake contributes minimum in overall delay ( T1<3ms)

• 4 way handshake doesn’t contribute major delay (T3<7ms)

• Major delay contributor is from EAP authentication with chosen methods (T2)– Potential Reasons 1) Certificates verification 2) Finite Field Prime number modular calculation and DLC calculation

• EAP-PSK demonstrates ideal performance in key establishment and is suitable for FILS authentication (with <20ms) .

• EAP-TLS with X.509 certificate based authentication options and key establishment imposes tight time budget in satisfying the performance objectives of TGai.

•

Rob Sun etc, Huawei.Slide 12

RSNA authentication T1 (ms) T2 in Client(ms) T2 in Server(ms) T3(ms) Total in client (ms) Total in Server

(ms) Total in Serialized

operation (ms)

EAP-PSK 2.584 4.83375 4.83375 6.891258 14.309008 14.309008 19.142758

EAP-TLS(DHE-DSS-1024) 2.584 198.8564 198.8564 6.891258 208.331658 208.331658 407.188058

EAP-TLS(RSA 1024) 2.584 9.869796 27.568796 6.891258 19.345054 37.044054 46.91385

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Further discussion

• Even though the choice of EAP methods are out of scope of IEEE 802 working group, would it be necessary to promote EAP-PSK as the candidate for the FILS authentication specific method?

• DHCP and DNS are both the major contributors of the delay, pre-establishment should be ideal for TGai.

Rob Sun etc, Huawei.Slide 13

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

References

• RFC 5216

• RFC 4764

• RFC 2246 and RFC 2246-bis-13

• Draft P802.11REVmb_D12.0

• FIPS SP 800 56A

• FIP 140-2 annex C

• RSA PKCS #1

•

Rob Sun etc, Huawei.Slide 14

Jan 2012

doc.: IEEE 802.11-12/0041r1

Submission

Performance of Public-Key Cryptograph

• Reference:

I. Branovic, R. Giorgi, E. Martinelli, "Memory Performance of Public-Key cryptography Methods in Mobile Environments", ACM SIGARCH Workshop on MEmory performance: DEaling with Applications, systems and architecture (MEDEA-03), New Orleans, LA, USA, Sept. 2003, pp. 24-31.

Jan 2012

Rob Sun etc, Huawei.Slide 15

doc.: IEEE 802.11-12/0041r1

Submission

Questions & Comments

Slide 16 Rob Sun etc, Huawei.

Jan 2012