Generating Random Numbers And Keys; Key Backup - Entrust nShield Security Manual

for use.
NIST SP 800-57 Part 1 Revision 4
and the risk factors that should be considered when determining cryptoperiods. Setting
a cryptoperiod limits, amongst other things, the amount of data exposure if a key is
compromised. You are advised to perform a threat analysis, considering the sensitivity of
your data and what controls you have in place to mitigate compromise, to determine
appropriate cryptoperiods for keys protecting that data.
In terms of the key management schema the following cryptoperiod rules must be
applied:
• Application keys must have a cryptoperiod assigned to them
• The Security World must have a cryptoperiod, as the Security World keys (e.g.
module keys) are used to protect application keys. The cryptoperiod of the Security
World must therefore be greater than or equal to the cryptoperiod of any application
key.
• Whenever an application key reaches the end of its cryptoperiod it must be revoked.
Whenever a Security World reaches the end of its cryptoperiod, a new Security
World must be initialized under a new ACS and new application keys generated. The
old Security World's ACS must be destroyed.
• Security World application keys can be created with a timeout and/or a usage value
to help manage cryptoperiods. Additionally in Common Criteria CMTS mode
application keys can use max timeout and max usage parameters to manage
cryptoperiods. Note that softcard protected application keys can't set a usage or
timeout limit as there is no option to set this in the ppmk utility. The cryptoperiods
for infrastructure keys can be managed manually by deleting a key when it has
reached the end of its cryptoperiod. This may require re-initialization of the Security
World.

7.5. Generating random numbers and keys

The nShield HSM includes a certified random number generator that uses a hardware
based source of entropy. This provides greater security than a random number generator
that uses a non-hardware based source of entropy that is typically provided by general
purpose computers. Therefore, always use the nShield HSM to generate random numbers
and keys.

7.6. Key backup

The sensitive Security World data e.g. application key blobs, stored on the host or RFS is
encrypted using the Security World key. You must regularly back up all the data stored in
the Key Management Data directory with your normal backup procedures. It would not
nShield® Security Manual
has sections describing the rationale for cryptoperiods
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