Italian Semester of Presidency of the European Union
EUROPEAN CONFERENCE OF MINERVA
Quality for cultural Web sites
Online Cultural Heritage for Research, Education
and Cultural Tourism Communities
Parma, 20-21 November 2003, Auditorium Paganini
Theodore S. Papatheodorou
(High Performance Information Systems Laboratory University of PatrasGreece)
Dimitris K. Tsolis
(High Performance Information Systems LaboratoryUniversity of PatrasGreece)
(Excellence Centre for Communication and Media Integration, University
of Florence Italy)
(National Inter-university Consortium for TelecommunicationsUniversity
of Florence Italy)
Technologies for IPR and data protection
Due to the large diffusion of the Internet, multimedia systems
in general are getting more and more importance and a new and unusual
way to distribute some information, such as cultural content for
this specific case, is offered. The chance to be able to look at
works of art in an interactive manner has led to the birth of many
virtual museums and art galleries all over the web; moreover the
owners of image databases and the managers of Cultural Heritage
are deeply interested in the possibility of spreading their goods
to the larger number of worldwide users.
At the same time, IPR protection of cultural content is gradually
becoming a critical issue primarily for the following reasons:
- Advances in technology have improved the ability to reproduce,
distribute, manage and publish information: reproduction costs
are much lower for both legitimate IPR holders (content owners)
and those infringing intellectual property legislation, and digital
copies are perfect replicas. Computer networks have changed the
economics of distribution: networks enable the distribution of
multimedia content worldwide, cheaply and quickly. As a consequence,
it is easier and less expensive both for the rights holder to
distribute a work and for an individual to make and distribute
unauthorized copies. Finally, the World Wide Web has fundamentally
altered the publication of information, allowing everyone to be
a publisher with worldwide reach.
- The production and sharing of information in electronic form
has been integrated into everyday life, directly affecting intellectual
property legislation. Today, casual everyday activities such as
downloading files, forwarding information found on the Web can
at times be violations of intellectual property laws. Other activities
such as making copies of information for private use may require
difficult interpretation of fair use provisions of the law to
simply justify their legality. Consequently, individuals in their
daily lives have the capability and the opportunity to access
and copy vast amounts of digital information, yet lack a clear
picture of what is acceptable or legal. On the other hand, the
necessary amendments of legislation in several cases do not fully
cope with the problem, resulting in certain legislative weaknesses.
- A fundamental problem is that institutions in the Cultural Heritage
sector want to make information widely available for educational,
non-commercial reasons, but the legal environment makes this difficult.
Where the rights-holders are known, this can be negotiated, but
the costs of clearing the rights for images taken by an individual
for non-commercial purposes can be prohibitively expensive.
It is the aim of this work to present current technological solutions
for IPR protection, which are designed, implemented and applied
through cultural applications, European projects, etc., and to discuss
recommendations, key points, disputes and limitations of these technological
Technological Solutions Overview
The technical part of the IPR protection of digital material problem
focuses on how to provide access without giving up control. A complete
technological schema which incorporates all possible means for IPR
- Technical Protection Means (TPM): that is a technology
that supports users, content owners and organizations to secure
and protect digital content (text, image, video, sound, graphics)
from unauthorized use. The definition implies the traceability
of an improper use. Proposed TPM are:
- Security and integrity of OS and computer networks.
- Encryption of transferred data.
- Watermarking of multimedia content.
- Tracking the use of the protected content.
- Digital Rights Management Systems (DRMS): that is systems
supporting the management of rights of digital content for providers
and users including time and usage based business models.
- Identification Systems.
- International metadata standards for IPR management.
- Rights management programming languages
- Delivery methods and technologies.
The above generic schema is applied, amongst other, to the Cultural
sector and provides the basis of an efficient IPR protection and
management of digital media.
In some papers and practices the term Digital Rights Management
includes also the Technical Protection Means. In these cases a complete
DRMS includes also watermarking software, data hiding technologies
and encryption. In this paper, Technical Protection Means are considered
as independent and stand - alone applications which serve as a platform
mainly for digital content protection from unauthorized use.
Technical Protection Means
The TPM used by practices and projects could be summarized below:
- Security and integrity features of computer operating systems
(include, for example, the traditional file access privileges enforced
by the system).
- Encryption, allows digital works to be scrambled so that
they can be unscrambled by legitimate users only.
- Persistent encryption, allows the consumer to use information
while the system maintains it in an encrypted form.
- Watermarking or data hiding, embeds information (e.g. about
ownership) into a digital work in much the same way that paper can
carry a watermark. A digital watermark can help owners track copying
and distribution of digital works.
- Trusted Systems. In one vision of the future, security
will become a major influence on the design of computing infrastructure,
leading to the development and widespread adoption of hardware based,
end-to-end systems that facilitate control of digital IP. The "trusted
systems" constitute an open research area.
- Protection Technologies for niches and Special - Purpose
Whether a TPM is successful lies on its technical strength and
depends also on both the product it protects and the business in
which it is deployed. The most important features are:
- Usability. A difficult to use protection system may discourage
users from using it.
- Appropriateness to the content. The cost of designing,
developing, and deploying the system has to be in harmony with the
type of the content. For inexpensive or already available in a reasonably
priced, non-Internet medium, there is no point to an expensive TPM
that drives up the price of Internet delivery.
- Appropriateness to the threat. Preventing honest customers
from giving copies to their friends may require nothing more that
a reasonably priced product, a good distribution system, and a clear
set of instructions. Preventing theft of extremely valuable content
that must at some point reside to a computer network requires a
very sophisticated TPM, and even the best available with current
technology may not be good enough.
- The cost-benefit analysis is a difficult but necessary
In the following, a more detailed description about data hiding
is given, since this technology still appears a novelty for most
of the people working in the Cultural Heritage sector.
3.1 Data hiding technologies
Digital watermarking or data hiding is a multidisciplinary research
field that combines signal processing with cryptography, communication
and coding theory. More specifically, by data hiding we mean the
concealment of some information, also called digital watermark,
within a host digital media (digital images, sound, video and computer
graphics); the information is hidden within the data itself, instead
of being attached to the data as a header or as a separate file.
Concealment is achieved by modifying some features of the host media
in a way that the modifications are not perceived by a user, so
that the quality of the host data is not degraded by the embedding
process and also because in this case is it is more difficult to
remove the hidden data. For example, in the case of a digital image,
it is possible to embed the information into the spatial domain,
by properly changing some pixel colour values, or into a transformed
domain: in this case, a mathematical transformation (like a Discrete
Wavelet Transform or a Discrete Cosine Transform) is applied to
the image obtaining a new representation of the image itself; next,
some Transform coefficients are properly modified, and finally the
inverse transformation is carried out to obtain the modified image.
The casted information can be extracted afterwards from the modified
content by detecting with a proper decoder the modifications introduced
by the data hiding system.
Data hiding techniques were first applied to copyright protection
applications, where the embedded signal, i.e. the watermark, conveys
copyright-related information about the hosting data. The exact
content of the embedded information depends on the particular application
and may include the identity of the creator or the distributor of
the work, or of the customer whom the work was sold, or the licensing
terms between seller and purchaser. The casted information can be
used to demonstrate content ownership, content misappropriation
or as a proof of purchase, and to do so, these data must remain
intact after possible modifications of the work. In such an application,
it is required that the digital watermarking is robust (i.e. it
is resistant) to intentional or unintentional modifications of the
watermarked content carried out during its fruition, that could
delete of make unreadable the embedded information.
Later on, new application fields demonstrated to take advantage
of the use of data hiding: e. g. this technology can be useful to
verify whether the content has been modified since its distribution.
In such a case, a pattern, i.e. the watermark, is embedded into
digital data to verify whether the content (i.e. an image) has been
modified or falsified since its creation. The inserted data are
extracted from the possibly corrupted object and compared with the
original embedded code: if they match then the content is assumed
to be uncorrupted; otherwise, if the extracted code does not match
the embedded one, it means that tampering occurred. In this application,
it is required that the digital watermark is fragile (i.e. not resistant)
to modifications carried out to the watermarked content.
Data hiding can also be used to embed hidden labels and annotations
into the host data: in this case, the embedded code contains an
annotation with information about the content; for example, a digital
image of some Cultural Heritage could embed some information like
an Identification Image Number, the content owner, the time the
picture was taken, etc. Also in this case, not to lose the embedded
data the system must result robust against possible unintentional
manipulations of the image.