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

B.3.14.7 Key Control Information
March, 2007
Key control information is used, for example, to determine the keys and other information to be
used to process cryptographically protected information (e.g., decrypt or authenticate), to
identify the purpose of a key, or the entities that share the key (see Section 6.2.3).
Key control information should be backed up or archived for as long as the associated key needs
to be available.
B.3.14.8 Random Numbers
Random numbers are generated by random number generators. The backup or archiving of a
random number depends on how it is used.
B.3.14.9 Passwords
A password is used to acquire access to privileges by an entity. The loss of a password will deny
the privileges. If the password can be replaced in a timely fashion, then the password need not be
backed up. A password shall not be archived.
B.3.14.10 Audit Information
Audit information containing key management events shall be backed up and archived.
B.4 Key Recovery Systems
Key recovery is a broad term that may be applied to several different key recovery techniques.
Each technique will result in the recovery of a cryptographic key and other information
associated with that key (i.e., the keying material). The information required to recover that key
may be different for each application or each key recovery technique. The term “Key Recovery
Information” (KRI) is used to refer to the aggregate of information that is needed to recover or
verify cryptographically protected information. Information that may be considered as KRI
includes the keying material to be recovered or sufficient information to reconstruct the keying
material, other associated cryptographic information, the time when the key was created, the
identifier of the owner of the key (i.e., the individual, application or organization who created the
key or who own the data protected by that key) and any conditions that must be met by a
requestor to be able to recover the keying material.
When an organization determines that key recovery is required for all or part of its keying
material, a secure Key Recovery System (KRS) needs to be established in accordance with a well
defined Key Recovery Policy (see Appendix B.5). The KRS shall support the Key Recovery
Policy and consists of the techniques and facilities for saving and recovering the keying material,
the procedures for administering the system, and the personnel associated with the system.
When key recovery is determined to be necessary, the KRI may be stored either within an
organization (in backup or archive storage) or may be stored at a remote site by a trusted entity.
There are many acceptable methods for enabling key recovery. A KRS could be established
using a safe for keying material storage; a KRS might use a single computer that provides the
initial protection of the plaintext information, storage of the associated keying material and
recovery of that keying material; a KRS may include a network of computers with a central Key
Recovery Center; or a KRS could be designed using other configurations. Since a KRS provides
an alternative means for recovering cryptographic keys, a risk assessment should be performed
to ensure that the KRS adequately protects the organization’s information and reliably provides
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