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music without the appropriate license. Therefore, Ub
needs to obtain a license from LIS in order to listen
to the content. The process can be depicted in the
following: Ua gives music to Ub; Ub gets the
content and tries to open it using the player; The
player detects that the Ub doesn’t have the
appropriate license to listen to the content; The user
(Ub) contacts the COS and searches for the specific
music track; COS validates Ub on the AUS; Ub
negotiates with the COS the appropriate content
license conditions for the music; COS requests to the
LIS to produce a license with the appropriate
conditions negotiated for the content and for the Ub;
Ub downloads the license; The player renders the
music according to the license; The license is stored
securely on the player.
This is a typical case of super distribution,
controlled by DRM. However, in some situations, it
is not very practical. If we consider that Ub, would
just like to listen to the music one or two times
immediately, he would first have to acquire a
specific license for that purpose, which may take
some more time, and money. A variance from the
solution presented in this section is presented next.
This is the case in which Ua transfers not only
content but also some of its own rights to Ub.
3.3 Passing content and rights to a
friend
In fact, a more attractive scenario involves not only
the transfer of content, but also the transfer of usage
rights. This is the case, for instance, in which a User
wants to give its content to a friend and at the same
time, pass its own rights (or part of them) as well.
Figure 3: Give content and rights scenario
The user usage rights are expressed in ODRL
format, using some relevant fields, such as
‘keyvalue’, ‘uid’, ‘count’ and ‘individual’. These
fields are use in the license to personalize it to a
specific content and user. Considering this license,
the owner might be willing to give part of its rights
(the ability to listen to the music ten times) to a
friend.
This procedure can be described in the following
steps: Ua gives content to Ub; Ua also wishes to
transfer some of its own rights to Ub; Ua signals LIS
that he is going to transfer rights to Ub; LIS asks to
Ua what rights does he wish to transfer; LIS updates
Ua license; LIS produces Ub license; Ub plays the
content in the player; Ub downloads license from
LIS; Player renders content.
4 CONCLUSIONS
One of the business models that have been under
consideration for many years (super distribution)
involves the insertion of DRM functionalities into
the P2P mechanisms, enabling consumers to
continue to share freely content files through file
sharing networks but only in a way that ensures that
the usage occurs on terms established by the rights
owner. However, due to the lack of the protection
functionality required to support such models don’t
have much success. The majority of DRM systems
can be distinguished by two essential features: (a)
the ability to deliver content usage rules
independently of the content; (b) the persistency on
content protection when acquired by a user granting
the access and use according to the permissions
granted to that user. In this way, content downloaded
for use on a particular device cannot be transferred
to a second device unless the permission obtained by
the user for that content expressly permits such a
transfer.
OpenSDRM is according to these, implementing
a set of security functionalities that enables a P2P
network to support the most three common content
distribution business models: a) Subscription model
and Pay-per-view; b) Aggregator model and c) the
Reseller model.
Although content has its own security when
transferred from device terminals OpenSDRM
implements also a licence management process,
centralized on clearinghouses that enables and
ensures compatibility when a user need more rights
than the ones transferred. This service would
provide publishers with information about player
devices and also support to alternative business
models such as pay-per-view or subscription based
pricing models based on secure licenses issued.
Players with Internet connectivity could also support
DIGITAL MUSIC ELECTRONIC COMMERCE – Addressing the super distribution model
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