Chapter 6

Wireless USB Security

6.1Introduction

This chapter provides Wireless USB security-related information. It describes the security inherent in wired USB (USB 2.0). This inherent security establishes a baseline that a wireless version must meet to be successful. This chapter also describes the architecture, protocols, mechanisms, and USB framework extensions needed to meet this baseline.

When considering security solutions, one must keep in mind that no solution is currently or can be proven to be impervious. Security systems are designed not to explicitly stop the attacker, but rather to make the cost of a successful attack far higher than any gain the attacker might realize from the attack. For the sake of brevity, when we say that a particular solution prevents attacks, we mean that the solution meets the objective listed above. The solution is not impervious, but the cost of compromising the solution outweighs the gain to be realized.

6.1.1 Goal of USB Security

Wireless implementations of USB are wire-replacement technologies. The wire actually provides two services typically associated with security. It connects the nodes the owner/user specifically wants connected. It also protects all data in transit from casual observation or malicious modification by external agents. The goal of USB Security is to provide this same level of user-confidence for wirelessly connected USB devices.

Cable Ends define user’s connection choice

Cable protects data in-transit

Figure 6-1: Security provided by USB Cable

6.1.2 Security and USB

The USB core specification does not currently support a notion of security. Applications are free to build security on top of USB, but the USB core specification itself does not currently provide any level of security. A Wireless USB implementation built on the UWB radio requires some level of security. The owner/user’s data must be kept private and protected. Likewise, the owner/user’s equipment must be protected from unauthorized connections from potentially hostile agents.

Rather than fill this need specifically for a UWB connection, this chapter defines a base-level security architecture for USB in general. Defining the security architecture in general USB terms allows for common USB security managers on the host, regardless of the underlying media that the USB protocol is bound to. Security operations are handled via the USB control channel, allowing this specification to remain media independent.

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