![Fortress Technologies ES210 Скачать руководство пользователя страница 134](http://html.mh-extra.com/html/fortress-technologies/es210/es210_user-manual_2322466134.webp)
Bridge GUI Guide: Security Configuration
119
4.1.3
MSP Key Establishment
You can configure the method that the Bridge and its Secure
Clients (and other connecting controller devices) use to
establish data encryption keys.
NOTE:
On wire-
less networks, sep-
arate multicast packets
are sent for each config-
ured key group. To max-
imize throughput, limit
the number selected.
In
Normal
operating mode (Section 4.1.1) the Bridge supports
three Diffie-Hellman groups (DH groups) for key
establishment—identified by the size of the modulus, in
numbers of bits, used to generate the secret shared key:
DH-512
(
Normal
[non-FIPS] operating mode only)
DH-1024
(
Normal
[non-FIPS] operating mode only)
DH-2048
(default selection)
When operating the Bridge in
FIPS
cannot use DH-512 or DH-1024 key establishment, because
the smaller Diffie-Hellman group moduli are no longer
compliant with FIPS 140-2 Security Level 2.
When NSA (National Security Agency) Suite B
5
cryptography
is licensed on the Bridge, an additional elliptic curve Diffie-
Hellman key establishment method is available for selection:
Suite B
(specified by the NSA as compliant with the Suite B set
of cryptographic algorithms). When Suite B is not licensed on
the Bridge, the Bridge GUI displays a link to the features
licensing page (refer to Section 6.3).
While a Secure Client can employ only one key establishment
option at a time, the Bridge supports multiple key establishment
selections, allowing connecting Clients to use any enabled key
establishment option.
NOTE:
Secure Cli-
ent versions earli-
er than 3.1 support only
DH-512 key establish-
ment. If you need to
support pre-3.1 Secure
Client devices, you
must include DH-512.
A Secure Client logging on to the Bridge must use a key
establishment option enabled on the Bridge. For information on
configuring key establishment on Fortress Secure Clients, refer
to the Secure Client’s user guide.
When two Fortress controller devices are connected, they will
negotiate keys using the highest security option mutually
supported by the devices.
When Suite B key establishment has been licensed on the
Bridge, this option represents the highest available security.
NOTE:
DH-512 key
establishment can-
not be selected when a
32-digit Access ID (Sec-
tion 4.1.17) is in effect.
Larger key moduli equate to more security for the standard
Diffie-Hellman group key establishment options, as well.
DH-512 is therefore the least secure DH group, and if you do
not need the Bridge to support Secure Client versions earlier
than 3.1 (which require DH-512), Fortress recommends more
secure key establishment.
Larger key moduli result in somewhat longer initial connection
times.
Refer to the Suite B requirements specific to your site and
implementation for guidance on Suite B.
5. Refer to Footnote 1 on page 2.