Explanation
WS-Federation
Reference: Java Web Services: Up and Running" By Martin Kalin page 228

An audit trail is a set of records that collectively provide
documentary evidence of processing used to aid in tracing from
original transactions forward to related records and reports, and/or
backward from records and reports to their component source
transactions. Audit trails may be limited to specific events or may
encompass all of the activities on a system.
User audit trails can usually log:
All commands directly initiated by the user
All identification and authentication attempts
Files and resources accessed
It is most useful if options and parameters are also recorded from
commands. It is much more useful to know that a user tried to
delete a log file (e.g., to hide unauthorized actions) than to know the user merely issued the delete command, possibly for a personal data file.
*Answer "An audit trail is a device that permits simultaneous data processing of two or more security levels without risk of compromise." is a description of a multilevel devicE. A multilevel device is a device that is used in a manner that permits it to process data of two or more security levels simultaneously without risk of compromisE. To accomplish this, sensitivity labels are normally stored on the same physical medium and in the same form (i.e.,
machine-readable or human-readable) as the data being processed.
*Answer "An audit trail mediates all access to objects within the network by subjects within the network." refers to a network reference monitor, an access control concept that refers to an abstract machine that mediates all access to
objects within the network by subjects within the network.
* Answer "Audit trails are used to prevent access to sensitive systems by unauthorized personnel." is incorrect, because audit trails are detective, and the answer describes a preventative process, access control. Source:
NCSC-TG-001 A Guide to Understanding Audit in Trusted Systems
and DoD 5200.28-STD Department of Defense Trusted Computer
System Evaluation Criteria.

As stated in the dictionary, here are 3 definitions of procedure:
Its pretty visible that this is the term we are looking for as stated in the questions, you can check
your CISSP documentation too.

"MD4 MD4 is a one-way hash function designed by Ron Rivest. It produces 128-bit hash, or message digest, values. It is used for high-speed computation in software implementations and is optimized for microprocessors.
MD5 MD5 is the newer version of MD4. It still produces a 128-bit hash, but the algorithm is more complex, which makes it harder to break. MD5 added a fourth round of operations to be performed during the hashing functions and makes several of it mathematical operations carry out more steps or more complexity to provide a higher level of security.
MD2 MD2 is also a 128-bit one-way hash designed by Ron Rivest. It is not necessarily any weaker than the previously mentioned hash functions, but is much slower.
SHA SHA was designed by NIST and NSA to be used with DSS. The SHA was designed to be used with digital signatures and was developed when a more secure hashing algorithm was required for federal application. SHA produces a 160-bit hash value, or message digest. This is then inputted into the DSA, which computes the signature for a message. The message digest is signed instead of the whole message because it is a much quicker process. The sender computes a 160-bit hash value, encrypts it with his private key (signs it), appends it to the message, and sends it. The receiver decrypts the value with the sender's public key, runs the same hashing function, and compares the two values. If the values are the same, the receiver can be sure that the message has not been tampered with in transit. SHA is similar to MD4. It has some extra mathematical functions and produces a 160-bit hash instead of 128-bit, which makes it more resistant to brute force attacks, including birthday attacks.
HAVAL HAVAL is a variable-length one-way hash function and is the modification of MD5. It processes message blocks twice the size of those used in MD5; thus it processes blocks of 1,024 bits.
Pg. 508-509 Shon Harris CISSP Certification All-In-One Exam Guide