$ HMAC
(I) A keyed hash [R2104] that can be based on any iterated
cryptographic hash (e.g., MD5 or SHA-1), so that the cryptographic
strength of HMAC depends on the properties of the selected
cryptographic hash. (See: [R2202, R2403, R2404].)
Derivation: Hash-based MAC. (Compare: CMAC.)
Tutorial: Assume that H is a generic cryptographic hash in which a
function is iterated on data blocks of length B bytes. L is the
length of the of hash result of H. K is a secret key of length L
<= K <= B. The values IPAD and OPAD are fixed strings used as
inner and outer padding and defined as follows: IPAD = the byte
0x36 repeated B times, and OPAD = the byte 0x5C repeated B times.
HMAC is computed by H(K XOR OPAD, H(K XOR IPAD, inputdata)).
HMAC has the following goals:
- To use available cryptographic hash functions without
modification, particularly functions that perform well in
software and for which software is freely and widely available.
- To preserve the original performance of the selected hash
without significant degradation.
- To use and handle keys in a simple way.
- To have a well-understood cryptographic analysis of the
strength of the mechanism based on reasonable assumptions about
the underlying hash function.
- To enable easy replacement of the hash function in case a
faster or stronger hash is found or required.
$ honey pot
(N) A system (e.g., a web server) or system resource (e.g., a file
on a server) that is designed to be attractive to potential
crackers and intruders, like honey is attractive to bears. (See:
entrapment.)
Usage: It is likely that other cultures use different metaphors
for this concept. Therefore, to avoid international
misunderstanding, an IDOC SHOULD NOT use this term without
providing a definition for it. (See: Deprecated Usage under "Green
Book".)
$ host
1. (I) /general/ A computer that is attached to a communication
subnetwork or internetwork and can use services provided by the
network to exchange data with other attached systems. (See: end
system. Compare: server.)
2. (I) /IPS/ A networked computer that does not forward IP packets
that are not addressed to the computer itself. (Compare: router.)
Derivation: As viewed by its users, a host "entertains" them,
providing Application-Layer services or access to other computers
attached to the network. However, even though some traditional
peripheral service devices, such as printers, can now be
$ https
(I) When used in the first part of a URL (the part that precedes
the colon and specifies an access scheme or protocol), this term
specifies the use of HTTP enhanced by a security mechanism, which
is usually SSL. (Compare: S-HTTP.)
$ human error
(I) /threat action/ See: secondary definitions under "corruption",
"exposure", and "incapacitation".
$ hybrid encryption
(I) An application of cryptography that combines two or more
encryption algorithms, particularly a combination of symmetric and
asymmetric encryption. Examples: digital envelope, MSP, PEM, PGP.
(Compare: superencryption.)
Tutorial: Asymmetric algorithms require more computation than
equivalently strong symmetric ones. Thus, asymmetric encryption is
not normally used for data confidentiality except to distribute a
symmetric key in a hybrid encryption scheme, where the symmetric
key is usually very short (in terms of bits) compared to the data
file it protects. (See: bulk key.)
$ hyperlink
(I) In hypertext or hypermedia, an information object (such as a
word, a phrase, or an image, which usually is highlighted by color
or underscoring) that points (i.e., indicates how to connect) to
related information that is located elsewhere and can be retrieved
by activating the link (e.g., by selecting the object with a mouse
pointer and then clicking).
$ hypermedia
(I) A generalization of hypertext; any media that contain
hyperlinks that point to material in the same or another data
object.
$ hypertext
(I) A computer document, or part of a document, that contains
hyperlinks to other documents; i.e., text that contains active
pointers to other text. Usually written in HTML and accessed using
a web browser. (See: hypermedia.)
$ Hypertext Markup Language (HTML)
(I) A platform-independent system of syntax and semantics (RFC
1866) for adding characters to data files (particularly text
files) to represent the data’s structure and to point to related
data, thus creating hypertext for use in the World Wide Web and
other applications. (Compare: XML.)
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