User Guide
DDOC0108-000-A2
CNS4 CSfC
6 - 12
Operation
Revision 1.0
Zeroization affects only the ILE. The data on the FSM-C modules is still accessible:
•
If the FSM-C module can be placed in another CNS4 with the same DEK loaded in its ILE.
•
If the DEK can be restored / reloaded.
Data stored on the CNS4 will be encrypted using the ILE module and software encryption on the
FSM-C modules. In addition, data on the FSM-C module can be secured by:
•
Physically separating (removing) the FSM-C module from the ILE which holds the encryption
key,
•
Zeroizing (erasing) the encryption key (zeroizing the ILE).
In both cases, the encrypted data remains on the FSM-C module, but is unintelligible and
inaccessible. To destroy the data on the FSM-C module, the FSM purge command must be used.
This action actually overwrites all the data on the FSM-C modules. Refer to paragraph 11.2.11
for additional information.
6.4.2
Hardware Encryption Layer
6.4.2.1
LE Account - Internal / External Key Storage
NOTE
DEKs are created in two ways, depending on which Security Mode is selected at login.
The ILE has two security modes (Internal and External). Each mode will define how the Data
Encryption Key (DEK) management is performed. Table 6.2 describes the security modes. The
user may change the security modes as needed.
*
Requires the selection of NOT STORED storage option along with a host to generate and retain the DEK.
•
ILE Mode: security mode type. The security mode must be selected by user via user interface
on initial power up.
•
User Authentication: ILE user authentication is required to access available ILE services.
•
Authorized Services: ILE security modes restrict access to services until the user is identified
and granted access to perform requested service (identity based authorization).
•
DEK Generation: method used to create the encryption key. The DEK may be created by the
ILE (Internal Mode) or by the host and sent to the ILE (External Mode).
•
DEK Transport: is how the DEK is moved from the user's storage place to the ILE. If DEK
management is handled by the ILE host (External Mode) then the DEK must be passed to the
ILE via RS-232 or I2C. This DEK is passed in an encrypted form and may then be stored on
the ILE. When the ILE controls DEK management, the DEK is created by the ILE (Internal
Mode) and stored on the ILE. Therefore, the DEK never passes outside the ILE unit.
•
DEK Storage Location: is how and where the DEK is stored. The user selects one of three
storage options for the DEK (Not stored, SRAM, or EEPROM) when using the Internal or
External Mode.
Table 6.2
Security Modes
Feature
Internal
Mode
External
Mode
User Authentication Required
x
x
User Composed Key
x
ILE Generated Key
x
DEK is Internal to the ILE and is Not Accessible to the User
x
Data Recovery after Power cycle
x
x
Data Recovery after Zeroization*
x
Selectable Storage Location
x
x
User Must Execute a Key Transfer Procedure*
x
