Key Management: General
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8.1.5.3.4 RBG Seeds
A Random Bit Generator RBG is a device or algorithm that outputs a sequence of bits that is unpredictable; RBGs are often called Random Number Generators. Approved RBGs are
specified in [SP800-90]
. RBGs depend on the introduction of truly random bits called seeds, which are used to initialize an RBG and that must be kept secret. An initialized RBG is often
used to generate keys and other values requiring unpredictability. The seeds themselves shall not be used for any purpose other than RBG input. Seeds shall only be transmitted using
secure channels that protect the confidentiality and integrity of the seeds, as well as providing replay protection
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and mutual authentication
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.
8.1.5.3.5 Other Public and Secret Information
Public and secret information may be used during the seeding of an RBG see Section
8.1.5.3.4 or during the generation or establishment of keying material see
[SP800-56A] ,
[SP800-56B] and
[SP800-108] . Public information may be distributed; secret information
shall be protected in the same manner as a private or secret key during distribution. 8.1.5.3.6 Intermediate Results
Intermediate results occur during computation using cryptographic algorithms. These results shall not be distributed as or with the keying material.
8.1.5.3.7 Random BitsNumbers
Random bits or numbers are used for many purposes, including the generation of keys and nonces, and the issuing of challenges during communication protocols. Random bits may be
distributed, but whether or not confidentiality protection is required depends on the context in which the random bits are used.
8.1.5.3.8 Passwords
Passwords are used for identity authentication or authorization, and, in some cases, to derive keying material see
[SP800-132] . Passwords may be distributed, but their protection during
distribution shall be consistent with the protection required for their use. For example, if the password will be used to access cryptographic keys that are used to provide 128 bits of security
strength when protecting data, then the password needs to be provided with at least 128 bits of protection as well. Note that poorly selected passwords may not themselves provide the
required amount of protection for key access and are potentially the weak point of the process; i.e., it may be far easier to guess the password than to attempt to “break” the cryptographic
protection used on the password. It is the responsibility of users and organizations to select passwords that provide the requisite amount of protection for the keys they protect.
8.1.6 Key Registration Function
Key registration results in the binding of keying material to information associated with a particular entity. Keys that would be registered include the public key of an asymmetric key
pair and the symmetric key used to bootstrap an entity into a system. Normally, keys generated during communications e.g., using key-agreement schemes or key derivation functions would
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Assurance that a valid data transmission is not maliciously or fraudulently repeated or delayed.
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Authentication by each party in a transaction of the identity of the other party.
Key Management: General
98 not be registered. Information provided during registration typically includes the identifier of
the entity associated with the keying material and the intended use of the keying material e.g., as a signing key, data-encryption key, etc.. Additional information may include authorization
information or specify a level of trust. The binding is performed after the entity’s identity has been authenticated by a means that is consistent with the system policy see
Section 8.1.1 . The
binding provides assurance to the community-at-large that the keying material is used by the correct entity in the correct application. The binding is often cryptographic, which creates a
strong association between the keying material and the entity. A trusted third party performs the binding. Examples of a trusted third party include a Kerberos realm server or a PKI
certification authority CA. Identifiers issued by a trusted third party shall be unique to that party.
When a Kerberos realm server performs the binding, a symmetric key is stored on the server with the corresponding metadata. In this case, the registered keying material is maintained in
secure storage i.e., the keys are provided with confidentiality and integrity protection.
When a CA performs the binding, the public key and associated information often called attributes are placed in a public-key certificate, which is digitally signed by the CA. In this
case, the registered keying material may be made publicly available.
When a CA provides a certificate for a public key, the public key shall be verified to ensure that it is associated with the private key known by the purported owner of the public key. This
provides assurance of possession. When POP is used to obtain assurance of possession, the assurance shall be accomplished as specified in
Section 8.1.5.1.1.2 .
8.2 Operational Phase
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