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

3. Determined by a key update process (see Section 8.2.3.2), or
4. Derived from a master key (see Section 8.2.4).
March, 2007
8.1.5.2.1 Key Generation
Symmetric keys determined by key generation methods shall be either generated by an
Approved random number generation method, created from the previous key during a key update
procedure (see Section 8.2.3.2), or derived from a master key (see Section 8.2.4) using an
Approved key derivation function.
When split knowledge procedures are used, the key shall exist as multiple key components. The
keying material may be created and then split into components, or may be created as separate
components. Each key component shall provide no knowledge of the key value (e.g., each key
component must appear to be generated randomly). If knowledge of k (where k is less than or
equal to n) components is required to construct the original key, then knowledge of any k-1 key
components shall provide no information about the original key other than, possibility, its length.
Note: A suitable combination function is not provided by simple concatenation; e.g., it is not
acceptable to form an 80 bit key by concatenating two 40-bit key components.
All keys shall be generated within a FIPS 140-2 validated cryptographic module or obtained
from another source approved by the U.S. Government for the protection of national security
information.
8.1.5.2.2 Key Distribution
Keys generated in accordance with Section 8.1.5.2.1 as key encrypting keys (used for key
wrapping), as the initial key for key update, as master keys to be used for key derivation, or for
the protection of communicated information are distributed manually (manual key transport) or
using an electronic key transport protocol (electronic key transport).
Keys used only for the storage of information (i.e., data or keying material) should not be
distributed except for backup or to other authorized entities that may require access to the
information protected by the keys.
8.1.5.2.2.1 Manual Key Distribution
Keys distributed manually (i.e., by other than an electronic key transport protocol) shall be
protected throughout the distribution process. During manual distribution, secret or private keys
shall either be encrypted or be distributed using appropriate physical security procedures. If
multi-party control is desired, split knowledge procedures may be used as well. The manual
distribution process shall assure that:
1. The distribution of keys is from an authorized source,
2. Any entity distributing plaintext keys is trusted by both the entity that generates the keys
and the entity(ies) that receives the keys,
3. The keys are protected in accordance with Section 6, and
4. The keys are received by the authorized recipient.
When distributed in encrypted form, the key shall be encrypted by an Approved key wrapping
scheme using a key encrypting key that is used only for key wrapping, or by an Approved key
transport scheme using a public key transport key owned by the intended recipient. The key
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