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

March, 2007
the KRI when required. It is the responsibility of the organization that needs to provide key
recovery to ensure that the Key Recovery Policy, the key recovery methodology, and the Key
Recovery System adequately protect the KRI.
A KRS should:
1. Generate or provide sufficient KRI to allow recovery or verification of protected
information.
2. Ensure the validity of the saved key and the other KRI.
3. Ensure that the KRI is stored with persistence and availability that is commensurate with
that of the corresponding cryptographically protected data.
4. Any cryptographic modules used by the KRS shall be compliant with [FIPS140-2].
5. The KRS shall use FIPS-Approved or NIST recommended algorithms, when
cryptography is used.
6. The strength of any algorithms used to protect KRI shall be commensurate with the
sensitivity of the information associated with the KRI.
7. The KRS shall be designed to enforce the Key Recovery Policy (see Section B.5).
8. The KRS shall protect KRI against unauthorized disclosure or destruction. The KRS
shall verify the source of requests and ensure that only requested and authorized
information is provided to the requestor.
9. The KRS shall protect the KRI from modification.
10. The KRS shall have the capability of providing an audit trail. The audit trail shall not
contain the keys that are recovered or any passwords that may be used by the system. The
audit trail should include the identification of the event being audited, the time of the
event, the identifier of the user causing the event, and the success or failure of the event.
11. The KRS shall limit access to the KRI, the audit trail and authentication data to
authorized individuals.
12. It should not be possible to modify the audit trail.
B.5 Key Recovery Policy
For each system, application and cryptographic technique used, consideration shall be given as
to whether or not the keying material may need to be saved for later recovery of the keying
material to allow subsequent decryption or checking of the information protected by the keying
material. An organization that determines that key recovery is required for some or all of their
keying material should develop a Key Recovery Policy that addresses the protection and
continued accessibility of that information 35 (see [DOD-KRP]). The policy should address (at a
minimum):
1. The keying material that needs to be saved for a given application. For example, keys and
IVs used for the decryption of stored information protected by the keys and IVs may need
35 An organization’s key recovery policy may be included in its PKI Certificate Policy.
137