Beyond secure channels

Abstract

A Trusted Channel is a secure communication channel which is cryptographically bound to the state of the hardware and software configurations of the endpoints. In this paper, we describe secure and flexible mechanisms to establish and maintain Trusted Channels which do not have the deficiencies of previous proposals. We also present a concrete implementation proposal based on Transport Layer Security (TLS) protocol, and Trusted Computing technology. We use Subject Key Attestation Evidence extensions to X.509v3 certificates to convey configuration information during key agreement (TLS handshake). The resulting session key is kept within the Trusted Computing Base, and is updated in a pre-determined manner to reflect any detected change in the local configuration. This allows an endpoint to detect changes in the configuration of the peer endpoint while the Trusted Channel is in place, and to decide according to a local policy whether to maintain or tear down the Trusted Channel.

Principles of remote attestation

“…Another problem in achieving comprehensive information is that, although many researchers are developing specialized tools for measurement and attestation, including [23,32,42,10,2], these tools have not been integrated into a unifying, multi-purpose attestation architecture. Connecting these disparate viewpoints on a single system into a single comprehensive attestation platform will be a significant challenge.…”

User Centric Security Model for Tamper-Resistant Devices

“…A trusted channel is a secure channel that is cryptographically bound to the current state of the communicating parties [165]. This state can be a hardware and/or software con guration, and ideally, it will require a trustworthy component to validate that it is the same as claimed.…”

“…The concept of trusted channel protocols was put forward by Gasmi et al [165] along with the adaptation of the TLS protocol [100] to meet the trusted channel requirements.…”

“…These protocols include the Station-to-Station (STS) protocol [174], the Aziz-Di e (AD) protocol [175], the ASPeCT protocol [176,177], Just-Fast-Keying (JFK) [178], trusted TLS (T2LS) [165], SCP81 [169], Markantonakis-Mayes (MM) protocol [83], and the Sirett-Mayes (SM) protocol [173].…”

“…In this thesis, the T2LS protocol described by Gasmi et al [165] is used that is described in this section. The messages listed below are on top of the existing TLS protocol that we do not detail in this section.…”