1. Performance Analysis of 802.11 authentication and authorization
Jan 2012
doc.: IEEE /0041r0
Jan 2012
Performance Analysis of authentication and authorization
Date:
Authors:
Name
Affiliations
Address
Phone
Robert Sun; Yunbo Li; Edward Au; Phillip Barber
Huawei Technologies Co., Ltd.
Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1
Rob Sun etc, Huawei.
Rob Sun, Huawei

2. Jan 2012
doc.: IEEE /0041r0
Jan 2012
Abstract
This proposal provides analysis of primary delay contributors within RSNA security protocol in accordance with IEEE i.
Rob Sun etc, Huawei.
Rob Sun, Huawei

3. Conformance w/ TGai PAR & 5C
Jan 2012
doc.: IEEE /0041r0
Jan 2012
Conformance w/ TGai PAR & 5C
Conformance Question
Response
Does the proposal degrade the security offered by Robust Security Network Association (RSNA) already defined in ? No
Does the proposal change the MAC SAP interface?
Does the proposal require or introduce a change to the architecture?
Does the proposal introduce a change in the channel access mechanism?
Does the proposal introduce a change in the PHY?
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
Rob Sun etc, Huawei.
Rob Sun, Huawei

4. IEEE 802.11 EAP Authentication and Authorization Delay Contributors
Jan 2012
IEEE 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
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5. Jan 2012
.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.

6. Air Time of 802.1X EAPOL messages
Jan 2012
Air Time of 802.1X EAPOL messages
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 n)
Results:
EAPOL start air time = 369.1us
EAPOL identity request = 369.1us
EAPOL identity response = us
EAPOL success =369.1us
Total T1= us =2.5ms
Reference:
Draft P802.11REVmb_D12.0
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7. EAP Authentication and Key establishment
Jan 2012
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 A)
. 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 4 message handshake as per RFC 5216
Note 2: Wired Delay is non negligible but wasn’t calculated
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8. Performance of various EAP methods and EAP-PSK methods
Jan 2012
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
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9. Client and Server processing time
Jan 2012
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.

10. Client and Server processing time
Jan 2012
Client and Server processing time
EAP Methods
Client Processing time (ms)
Server Processing Time (ms)
EAP-PSK
EAP-TLS (DHE-DSS-1024)
EAP-TLS (RSA-1024)
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11. 4-Way Handshake Processing Time
Jan 2012
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
4 WAY handshake
Processing Time (ms)
Initialization
KDF functions and MIC
Air time
1.22
Total
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12. Total in Serialized operation (ms)
Jan 2012
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 hard problem
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.
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
EAP-TLS(DHE-DSS-1024)
EAP-TLS(RSA 1024)
Rob Sun etc, Huawei.

13. Jan 2012
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.

14. References RFC 5216 RFC 4764 RFC 2246 and RFC 2246-bis-13
Jan 2012
References
RFC 5216
RFC 4764
RFC 2246 and RFC 2246-bis-13
Draft P802.11REVmb_D12.0
FIPS SP A
FIP annex C
RSA PKCS #1
Rob Sun etc, Huawei.

15. Jan 2012
Questions & Comments
Rob Sun etc, Huawei.