2024-05-10Last updated
Prevent relay attacks on supported OSDP readers by configuring a maximum delay for card
authentication.
What you should know
During a relay attack, it takes longer than normal for the system to authenticate a
card because the attackers must relay messages to each other in the middle. For this reason,
relay attacks can be effectively prevented by setting a maximum delay for card authentication.
When the maximum delay is exceeded during a card read, the
Synergis™ Cloud Link unit does not proceed to make an access
decision, and the door remains locked.Note: No Access denied event is generated when
the maximum delay is exceeded.
Procedure
-
Log on to the
Synergis Cloud Link unit.
-
Click .
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In the Readers and associated MIFARE DESFire configurations
section, select the Proximity Check option beside one or more OSDP
readers.
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For each reader with Proximity Check enabled, enter a value in
milliseconds to define the maximum card authentication delay in the
ms field.
Tip: Relay attack prevention is enabled per reader. Since each reader's timing
is different, determine the average time that the reader takes to authenticate a
legitimate badge and add a small margin of error to calculate the maximum delay. The
suggested margin of error is 40 milliseconds.
To determine how long a card took to be
authenticated, go to . In the Logger drop-down, select
Syslog, and in the Filter by regex
field, enter SmartCard. Check the logs with the
SmartCard prefix for the authentication time.
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Click Save.
