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DigiCULT
.
Info
39
CWIS
C
OLLECTION
W
ORKFLOW
I
NTEGRATION
S
YSTEM
A
DAM
R
USBRIDGE
,
ERPANET T
ECHNICAL
A
NALYST
T
he National Science Foundation
funded CWIS Open Source soft-
ware (http://scout.wisc.edu/Projects/
CWIS/) is a tool to `assemble, organise, and
share collections of data about resources
[...] conforming to international and aca-
demic standards of metadata.' Many insti-
tutions and organisations maintain portals
of resources that can be accessed by a user.
This software enables staff to manage and
control the information with greater ease,
and provides a user with a higher degree of
interactivity with the information. The sys-
tem requires a Linux, Apache, MySQL and
PHP (LAMP) server configuration to run
and is licensed under the GNU General
Public License.
T
he system has been designed with
resource discovery in mind. It con-
forms to the OAI Protocol for Metadata
Harvesting and allows an RSS feed to be
generated and updated. The OAI protocol
provides search engines with information
about the collection, and the two features
combined improve the visibility of the con-
tent and the ease with which a user may dis-
cover specific and appropriate information.
T
o manage the portal, a clean admin-
istration interface is provided.
Administrators can edit the System, OAI or
RSS configurations, alter the metadata con-
figurations (to unique specifications if nec-
essary), edit and track user accounts, and
import and export data. Naturally, the add-
ing and editing of resources is a central part
of the system.
W
hen searching for information, it is
common for a user to spend a large
amount of time browsing through extrane-
ous or sub-standard resources. Rating and
Comment features provide peer reviews
of the value and content of the resource.
These lightweight additions can be very
useful to a user but can simply be ignored
if not needed. A recommendations feature
is provided to a user dependent upon how
they have rated other resources. Finally, it is
possible to set up a continuous search func-
tion providing a weekly e-mail contain-
ing new resources that have been added
according to a certain set of criteria.
T
here are many techniques that can be
used to generate a resource collec-
tion and it is difficult to classify a leading
method. CWIS contains many features that
should be included in a resource collection
and I, for one, will be watching this project
with interest.
M
ore information about the
Collection Workflow Integration
System is available from http://scout.wisc.
edu/Projects/CWIS/.
T
he new DigiCULT Technology Watch
Report 2 (available at http://www.
digicult.info/pages/techwatch.php) has a
chapter discussing Rights Management for
cultural and scientific heritage institutions.
Digital media are particularly susceptible to
illegal copying and distribution and her-
itage institutions who wish to make their
digital collections available online should
be cautious about presenting digital objects
without a way to identify ownership, copy-
right and usage rights. The Technology Watch
Report 2 identifies various ways in which an
institution can protect its digital holdings
from fraudulent use; however, this short
article concentrates on protecting images
using steganography techniques.
WHAT IS STEGANOGRAPHY?
T
he word `steganography' comes from
Greek and means literally covered writ
-
ing. Today it refers to hiding one piece of
information inside another, a common
example being the invisible watermarking
of images. Other steganography methods
include invisible inks (for example, lemon
juice which darkens when heated), micro-
dots (up to one page can be hidden in the
space of a dot), and digital signatures (a
cryptographic method of verifying infor-
mation). In a nutshell, steganography is any
way of communicating that hides the actual
fact of communication itself.
A
n early example, from the Histories
of Herodotus, was the use of stega-
nography in the wax-covered tablets used
in ancient Greece for writing. When send-
ing delicate information that needed to
escape the notice of sentries, the wax could
be scraped off the tablets, a message writ-
ten on the wood beneath and the wax
reapplied with a decoy message. A different
method was to shave the head of a mes-
senger and tattoo a secret message onto his
scalp, which would be undetected once his
hair had grown back. However, the art and
science of steganography has come a long
way since then! It is not only messages in
the form of text and images that can be
concealed, but more advanced tools such
as agents or programs. This means that, in
addition to `passive' data, steganography can
be used to carry `active' data that can per-
form actions. Examples could include ini-
tiating a registration program when a file is
downloaded, or `self-destructing' if the cri-
teria for owning the file are not met.
A
digital watermark is an image, digit-
al signal or pattern that is embedded
permanently into another media type and
can act as a digital signature for any copies
made of that digital object. Watermarks can
be visible (for example, a fairly unobtrusive
logo which displays property ownership
and can dissuade illicit use of the image)
S
TEGANOGRAPHY
E
XPLAINED