Using secure coprocessors to enforce network access policies in enterprise and ad hoc networks

Nowadays, network security is critically important. Enterprises rely on networks to improvetheir business. However, network security breaches may cause them loss of millions of dollars.Ad hoc networks, which enable computers to communicate wirelessly without the need forinfrastructure support, have been attracting more and more interests. However, they cannotbe deployed effectively due to security concerns.Studies have shown that the major network security threat is insiders (malicious orcompromised nodes). Enterprises have traditionally employed network security solutions(e.g., firewalls, intrusion detection systems, anti-virus software) and network access controltechnologies (e.g., 802.1x, IPsec/IKE) to protect their networks. However, these approachesdo not prevent malicious or compromised nodes from accessing the network. Many attacksagainst ad hoc networks, including routing, forwarding, and leader-election attacks, requiremalicious nodes joining the attacked network too.This dissertation presents a novel solution to protect both enterprise and ad hoc networksby addressing the above problem. It is a hardware-based solution that protects a networkthrough the attesting of a node's configuration before authorizing the node's access to thenetwork. Attestation is the unforgeable disclosure of a node's configuration to another node,signed by a secure coprocessor known as a Trusted Platform Module (TPM).This dissertation makes following contributions. First, several techniques at operatingsystem level (i.e., TCB prelogging, secure association root tripping, and sealing-free attestation confinement) are developed to support attestation and policy enforcement. Second, two secure attestation protocols at network level (i.e., Bound Keyed Attestation (BKA) andBatched Bound Keyed Attestation (BBKA)) are designed to overcome the risk of a man-inthe-middle (MITM) attack. Third, the above techniques are applied in enterprise networks todifferent network access control technologies to enhance enterprise network security. Fourth,AdHocSec, a novel network security solution for ad hoc networks, is proposed and evaluated. AdHocSec inserts a security layer between the network and data link layer of the networkstack. Several algorithms are designed to facilitate node's attestation in ad hoc networks,including distributed attestation (DA), and attested merger (AM) algorithm