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

March, 2007
All cryptographic information requires integrity protection. Integrity shall be provided by
physical mechanisms, cryptographic mechanisms or both.
Physical mechanisms include:
1. A validated cryptographic module or operating system that limits access to the stored
information,
2. A computer system or media that is not connected to other systems,
3. A physically secure environment that is outside a computer system (e.g., in a safe with
limited access) with appropriate access controls.
Cryptographic mechanisms include:
a. A cryptographic integrity mechanism (e.g., MAC or digital signature) that is computed
on the information and is later used to verify the integrity of the stored information.
b. Performing the intended cryptographic operation. If the received information is incorrect,
it is possible that the keying material may have been corrupted.
If the cryptographic information needs to be restored when an error is detected, multiple copies
of the information should be maintained in physically separate locations (i.e., in backup or
archive storage; see Sections 8.2.2.1 and 8.3.1). The integrity of each copy should be
periodically checked.
6.2.2.3 Confidentiality
One of the following mechanisms shall be used to provide confidentiality for private or secret
keying material in storage:
1. Encryption with an Approved algorithm in a FIPS 140-2 cryptographic module. It
shall be no easier to recover the key encrypting key than it is to recover the key being
encrypted,
-OR-
2. Physical protection provided either by a FIPS 140-2 (level 2 or higher) cryptographic
module,
-OR-
3. By secure storage (e.g., safe or protected area) with controlled access.
6.2.2.4 Association with Usage or Application
Cryptographic information is used with a given cryptographic mechanism (e.g., digital signatures
or key establishment) or with a particular application. Protection shall be provided to ensure that
the information is not used incorrectly (e.g., not only must the usage or application be associated
with the keying material, but the integrity of this association must be maintained). This
protection can be provided by separating the cryptographic information from that of other
mechanisms or applications, or by appropriate labeling of the information. Section 6.2.3
addresses the labeling of cryptographic information.
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