Part 1: General - Computer Security Resource Center - National ...

Type of Key Backup?
March, 2007
Public static key agreement key OK; its presence in a public-key certificate that is available
elsewhere may be sufficient.
Private ephemeral key agreement
key
Public ephemeral key agreement
key
No
Symmetric authorization key OK
Private authorization key OK
OK if needed for reconstruction during key recovery
Public authorization key OK; its presence in a public-key certificate that is available
elsewhere may be sufficient.
Table 8: Backup of other cryptographic or related information
Type of Keying Material Backup?
Domain parameters OK
Initialization vector OK, if necessary
Shared secret No
RNG seed No
Other public information OK
Intermediate results No
Key control information (e.g.,
IDs, purpose, etc.)
OK
Random number Depends on application or use of the RNG
Passwords OK
Audit information OK
8.2.2.2 Key Recovery Function
Keying material that is in active memory or stored in normal operational storage may sometimes
be lost or corrupted (e.g., from a system crash or power fluctuation). Some of the keying material
is needed to continue operations and cannot easily be replaced. An assessment needs to be made
of which keying material needs to be preserved for possible recovery at a later time.
The decision as to whether key recovery is required should be made on a case by case basis. The
decision should be based on:
1. The type of key (e.g., private signature key, symmetric data encryption key),
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