User's Manual

SEL-3022 Transceiver Instruction Manual Date Code 20050615
Wireless Operator Interface Security
The SEL Security Application
C.18
Cryptographic Manual—Do Not Copy
value that is less than, or equal to, the sequence number value received in the last
frame. It is exceedingly difficult to maliciously alter the sequence number in any given
frame to bypass this functionality because the sequence number field is protected by
the strong cryptographic authentication mechanisms provided by the HMAC SHA-1
function. Because of the protection these mechanisms provide, an attacker cannot
capture a frame, previously transmitted in a given wireless operator interface session,
and resend the frame to the SEL-3022 to cause harmful actions.
Conclusions
Two independent layers of cryptographic security protect the SEL-3022 wireless
operator interface: the 802.11b wireless interface module WEP encryption function,
and the AES encryption and HMAC SHA-1 authentication functions in the SEL
Security Application. For an attacker to compromise the SEL-3022 operator interface,
both the WEP encryption and the SEL Security Application have to be defeated. As
shown in the discussion above, the probability of an attacker accomplishing this is
statistically impossible.
Additional Protection for Windows XP Users
IMPORTANT: Windows XP users can further protect their
computer during setup by enabling a firewall on their
wireless connection. This firewall protects your computer
from unauthorized users who might try an ad hoc
connection. This will not impact your ability to configure
the SEL-3022.
Follow these steps to enable a firewall on Windows XP Wireless Connection.
Step 1. Click on the Start menu, select Settings, then Network
Connections, and then Wireless Connection.
Step 2. Click on the Wireless connection you used to communicate with the
SEL-3022 (example: Wireless Connection 2).
Step 3. Click on Properties, then the Advanced tab.
Step 4. Click on the box beside Protect my computer and network by
limiting or preventing access to this computer from the Internet.
Step 5. Click OK.
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