Teledyne LeCroy Merlin Mobile - Users Manual - Manual (Page 156)

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Merlin Mobile User’s Manual CATC SW Version 2.0
When the right PIN is entered, the Slave begins an encryption setup
dialogue with the Master. At the beginning of this dialogue, the Slave and
the Master agree on a Link Key. A Link Key is a 128-bit value that the two
devices use for authentication. When the Slave and Master agree on a Link
Key, the Slave then negotiates for the transfer of the Encryption Key from
the Master device. The Encryption Key is used to encrypt and decrypt
messages. Once the Encryption Key is transferred, both devices use it to
encrypt all subsequent communications.
In order for Merlin Mobile to decode encrypted traffic, it needs the Link Key
for each Master-Slave connection for which encryption will be used. If you
know the Link Key, you can enter the Key into the Encryption Options
dialog box. If you do not know it, you give Merlin Mobile the PIN for a
device and allow Merlin Mobile to discover the Link Key on its own. Once
Merlin Mobile has the Link Key, it can capture the rest of what it needs by
listening to the Master and Slave devices as they negotiate for the
Encryption Key.
Configuring Merlin Mobile for Encryption
For Merlin Mobile to successfully decrypt traffic, two steps need to be
performed: 1) Merlin Mobile needs to be given the PIN or Link Key for
each Master-Slave connection; and 2) Recording needs to be begun before
the Slave connects to the Master. If recording is begun prior to the creating
the Master-Slave connection, Merlin Mobile will be able to obtain the
encryption key and decode encrypted traffic.
The following steps show how to configure Merlin Mobile for encrypted
traffic.
Note Be sure to begin the following process prior to connecting your Slave device to
the Master or Merlin Mobile will not be able to capture the Link Key.
Step 1 Select View >Device List
The Device List appears.