A User Centric Security Model for Tamper-Resistant Devices

6.1 Introduction
6.1 Introduction
Secure Channel Protocols (SCPs) are designed to provide a secure communications channel.
They typically start by providing entity authentication and authenticated key establishment.
There are many dierent protocols proposed for internet and smart card
environments that satisfy dierent (pre-dened) design goals. Not all protocols can be
used for every possible scenario; if this was possible, we would not have the diversity of
SCPs that we have today.
The UCTD architecture has its own set of security and operational goals for an SCP has
to satisfy. These goals range from traditional SCP ones like entity authentication and
mutual key generation, to UCOM-specic requirements like smart card state validation.
In this chapter, we examine a non-exhaustive list of security and operational goals for the
UCTD environment. The dened list is considered adequate to gauge the basic security
requirements of the UCTD and related stakeholders (section 3.5).
An SCP in the UCTD can take many dierent forms, and we discuss three possible variants.
The rst two variants are based on the UCOM architecture and the dierences between
them is determined by who initiates the protocol, and whether it is a smart card or an
SP. The third protocol caters to the CASC environment and involves an administrative
authority during the protocol execution.
The proposed protocols are informally analysed, based on the pre-dened security and
operational requirements. We also provide a comparison between the proposed protocols
and a set of protocols ranging from the internet and smart card environments. We also
provide a formal-mechanical proof for the proposed protocols using the CasperFDR tool,
along with test implementation and performance measurements.
Structure of the Chapter: The chapter begins with a discussion of the rationale behind
the SCPs in section 6.2. In this section we also discuss minimum security and operational
requirements stipulated for the UCTD environment. Section 6.3, discusses the proposed
SCP that is initiated by an SP, and section 6.4 details the SCP initiated by a smart
card. The SCP that focuses on the administrative management architecture of the UCTD
(section 5.4.1) is described in section 6.5. Section 6.6 provides the informal analysis,
mechanical formal analysis and test implementations of the proposed protocols.
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