A User Centric Security Model for Tamper-Resistant Devices

3.4 User Centric Smart Card Ownership Model (UCOM)
ZC6.5). Like WfSC, they also support the FAT le system, but unlike any other smart
card framework, they support oating-point numbers natively [6]. Although these are less
expensive than other options available to customers, they have not seen an exponential
growth such as Java Card.
3.4 User Centric Smart Card Ownership Model (UCOM)
The UCOM provides to dierent entities the architectural, operational, and security framework
needed to support the delegation of smart card ownership to its users. In this section,
a detailed description of the UCOM is provided, dening the basic working principles of
the UCOM along with a description of the UCOM components. Figure 3.5 illustrates the
basic architecture of the model.
User Centric
Smart Card
(UCSC)
Supplier
1. Smart Card Ordered
2. Smart Card Delivered
5. Service Request
Cardholder
8. Service Response
3. Application Lease Request
4. Application Leased
7. Response
6. Request
Smart Card
Based Service
Provider
Service Access Point
Figure 3.5: Overview of the User Centric Smart Card Ownership Model (UCOM)
In the UCOM, a card issuer is denoted as a Service Provider (SP). An SP and a card
issuer represent the same entity in dierent contexts of UCOM and ICOM, respectively.
The main dierence between an issuer and an SP is that a card issuer provides a smart
card's hardware and application(s) to their customers, whereas an SP only oers smart
card application(s) that can be downloaded to a customer's smart card on request.
The aim of the UCOM is not to replace users with card issuers as the open card initiative
(see section 2.4.2.1) does. The UCOM ensures that the same level of security and
application control is provided to an SP as in the ICOM, while provisioning the freedom
of choice to individual cardholders. Going back to the list of privileges for ICOM (section
3.2), the UCOM transfers the privileges (rights) one, two and four to the smart card users.
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