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

March, 2007
re-derivation) of the keying material. Acquiring the keying material from backup or by
reconstruction is commonly known as key recovery (see Section 8.2.2.2).
At the end of a key’s cryptoperiod, a new key needs to be available to replace the old key if
operations are to be continued. This can be accomplished by re-keying (see Section 8.2.3.1), key
update (see Section 8.2.3.2), or key derivation (see Section 8.2.4). A key shall be destroyed in
accordance with Section 8.3.4 and should be destroyed as soon as that key is no longer needed in
order to reduce the risk of exposure.
8.2.1 Normal Operational Storage Function
The objective of key management is to facilitate the operational availability of keying material
for standard cryptographic purposes. Usually, a key remains operational until the end of the
key’s cryptoperiod (i.e., the expiration date). During normal operational use, keying material is
available either in the device or module (e.g., in RAM) or in an immediately accessible storage
media (e.g., on a local hard disk).
8.2.1.1 Device or Module Storage
Keying material may be stored in the device or module that adds, checks, or removes the
cryptographic protection on information. The storage of the keying material shall be consistent
with Section 6.2.2, as well as with [FIPS140-2].
8.2.1.2 Immediately Accessible Storage Media
Keying material may need to be stored for normal cryptographic operations on an immediately
accessible storage media (e.g., a local hard drive) during the cryptoperiod of the key. The storage
requirements of Section 6.2.2 shall apply to this keying material.
8.2.2 Continuity of Operations Function
Keying material can become lost or unusable due to hardware damage, corruption or loss of
program or data files, or system policy or configuration changes. In order to maintain the
continuity of operations, it is often necessary for users and/or administrators to be able to recover
keying materials from back-up storage. However, if operations can be continued without the
backup of keying material (e.g., by re-keying), or the keying material can be recovered or
reconstructed without being saved, it may be preferable not to save the keying material in order
to lessen the possibility of a compromise of the keying material or other cryptographic related
information.
The compromise of keying material affects continuity of operations (see Section 8.4). When
keying material is compromised, the continuity of operations requires the establishment of
entirely new key material (see Section 8.1.5), following an assessment of what keying material is
affected and must be replaced.
8.2.2.1 Backup Storage
The backup of keying material on an independent, secure storage media provides a source for
key recovery (see Section 8.2.2.2). Backup storage is used to store copies of information that is
also currently available in normal operational storage during a key’s cryptoperiod (i.e., in the
cryptographic device or module, or on an immediately accessible storage media - see Section
8.2.1.1). Not all keys need be backed up. The storage requirements of Section 6.2.2 apply to
keying material that is backed up. Tables 7 and 8 provide guidance about the backup of each type
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