Teledyne Lecroy Frontline BPA 600, Руководство пользователя по аппаратному и программному обеспечению, Страница: 36 / 348

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Third, if you know the Link Key in advance you may enter it directly. Select
Link Key
in the Encryption list
and then enter the Link Key in the edit box. If the link key is already in the database, the Link Key is
automatically entered in the edit box after the Master and Slave have been selected. You can also pick
Choose Pair from Device Database
to select a Master, Slave and Link Key from the Device Database .
1. Select an Encryption option.
2. Enter a value for the encryption.
The
Current Link Key
field displays the currently provided
Link Key
and the date and time the key
was provided. The status of the
Link Key
is displayed with the following icons:
Icon Link Key Status
Valid
Not Valid
Connection
Attempted But
Failed
LE Encryption
1. Enter the New Long Term Key for the LE
Encryption.
The long term key is similar to the Link key in
Classic. It is a persistent key that is stored in both
devices and used to derive a fresh encryption
key each time the devices go encrypted.
Learn more about the Long Term Key.
The Long Term Key is similar to the Link key in
Classic; it is a persistent key that is stored in both
devices and used to derive a fresh encryption
key each time the devices go encrypted.
There are a few differences though:
In Classic the Link key is derived from inputs from both devices and is calculated in the same way
independently by both devices and then stored persistently. The link key itself is never transmitted
over the air during pairing.
In LE, the long term key is generated solely on the slave device and then, during pairing, is distributed
to a master device that wants to establish an encrypted connection to that slave in the future. Thus the
long term key is transmitted over the air, albeit encrypted with a one-time key derived during the
pairing process and discarded afterwards (the so called short term key).
Unlike the link key, this long term key is directional, i.e. it is only used to for connections from the
master to the slave (referring to the roles of the devices during the pairing process). If the devices also
want to connect the other way round in the future, the device in the master role (during the pairing
process) also needs to send its own long term key to the device in the slave role during the pairing
process (also encrypted with the short term key of course), so that the device which was in the slave
Chapter 3 Configuration Settings TELEDYNE LECROY
Frontline BPA 600 Hardware & Software User Manual 28