22,333 research outputs found
Tree-formed Verification Data for Trusted Platforms
The establishment of trust relationships to a computing platform relies on
validation processes. Validation allows an external entity to build trust in
the expected behaviour of the platform based on provided evidence of the
platform's configuration. In a process like remote attestation, the 'trusted'
platform submits verification data created during a start up process. These
data consist of hardware-protected values of platform configuration registers,
containing nested measurement values, e.g., hash values, of loaded or started
components. Commonly, the register values are created in linear order by a
hardware-secured operation. Fine-grained diagnosis of components, based on the
linear order of verification data and associated measurement logs, is not
optimal. We propose a method to use tree-formed verification data to validate a
platform. Component measurement values represent leaves, and protected
registers represent roots of a hash tree. We describe the basic mechanism of
validating a platform using tree-formed measurement logs and root registers and
show an logarithmic speed-up for the search of faults. Secure creation of a
tree is possible using a limited number of hardware-protected registers and a
single protected operation. In this way, the security of tree-formed
verification data is maintained.Comment: 15 pages, 11 figures, v3: Reference added, v4: Revised, accepted for
publication in Computers and Securit
Exploring the Integration of Memory Management and Trusted Computing
This thesis addresses vulnerabilities in current Trusted Computing architecture by exploring a design for a better Trusted Platform Module (TPM); one that integrates more closely with the CPU\u27s Memory Management Unit (MMU). We establish that software-based attacks on trusted memory can be carried out undetectably by an adversary on current TCG/TPM implementations. We demonstrate that an attacker with sufficient privileges can compromise the integrity of a TPM-protected system by modifying critical loaded code and static data after measurement has taken place. More specifically, these attacks illustrate the Time Of Check vs. Time of Use (TOCTOU) class of attacks. We propose to enhance the MMU, enabling it to detect when memory containing trusted code or data is being maliciously modified at run-time. On detection, it should be able to notify the TPM of these modifications. We seek to use the concepts of selective memory immutability as a security tool to harden the MMU, which will result in a more robust TCG/TPM implementation. To substantiate our ideas for this proposed hardware feature, we designed and implemented a software prototype system, which employs the monitoring capabilities of the Xen virtual machine monitor. We performed a security evaluation of our prototype and validated that it can detect all our software-based TOCTOU attacks. We applied our prototype to verify the integrity of data associated with an application, as well as suggested and implemented ways to prevent unauthorized use of data by associating it with its owner process. Our performance evaluation reveals minimal overhead
SGXIO: Generic Trusted I/O Path for Intel SGX
Application security traditionally strongly relies upon security of the
underlying operating system. However, operating systems often fall victim to
software attacks, compromising security of applications as well. To overcome
this dependency, Intel introduced SGX, which allows to protect application code
against a subverted or malicious OS by running it in a hardware-protected
enclave. However, SGX lacks support for generic trusted I/O paths to protect
user input and output between enclaves and I/O devices.
This work presents SGXIO, a generic trusted path architecture for SGX,
allowing user applications to run securely on top of an untrusted OS, while at
the same time supporting trusted paths to generic I/O devices. To achieve this,
SGXIO combines the benefits of SGX's easy programming model with traditional
hypervisor-based trusted path architectures. Moreover, SGXIO can tweak insecure
debug enclaves to behave like secure production enclaves. SGXIO surpasses
traditional use cases in cloud computing and makes SGX technology usable for
protecting user-centric, local applications against kernel-level keyloggers and
likewise. It is compatible to unmodified operating systems and works on a
modern commodity notebook out of the box. Hence, SGXIO is particularly
promising for the broad x86 community to which SGX is readily available.Comment: To appear in CODASPY'1
Fragmentation of confidential objects for data processing security in distributed systems
This paper discusses how object orientation in application design enables confidentiality aspects to be handled more easily than in conventional approaches. The idea, based on object fragmentation at design time, is to reduce processing in confidential objects; the more non confidential objects can be produced at design-time, the more application objects can be processed on untrusted shared computers. Still confidential objects must be processed on non shared trusted workstations. Rules and limits of object fragmentation are discussed together with some criteria evaluating trade-offs between fragmentation and performance
Supporting security-oriented, collaborative nanoCMOS electronics research
Grid technologies support collaborative e-Research typified by multiple institutions and resources seamlessly shared to tackle common research problems. The rules for collaboration and resource sharing are commonly achieved through establishment and management of virtual organizations (VOs) where policies on access and usage of resources by collaborators are defined and enforced by sites involved in the collaboration. The expression and enforcement of these rules is made through access control systems where roles/privileges are defined and associated with individuals as digitally signed attribute certificates which collaborating sites then use to authorize access to resources. Key to this approach is that the roles are assigned to the right individuals in the VO; the attribute certificates are only presented to the appropriate resources in the VO; it is transparent to the end user researchers, and finally that it is manageable for resource providers and administrators in the collaboration. In this paper, we present a security model and implementation improving the overall usability and security of resources used in Grid-based e-Research collaborations through exploitation of the Internet2 Shibboleth technology. This is explored in the context of a major new security focused project at the National e-Science Centre (NeSC) at the University of Glasgow in the nanoCMOS electronics domain
Security, Performance and Energy Trade-offs of Hardware-assisted Memory Protection Mechanisms
The deployment of large-scale distributed systems, e.g., publish-subscribe
platforms, that operate over sensitive data using the infrastructure of public
cloud providers, is nowadays heavily hindered by the surging lack of trust
toward the cloud operators. Although purely software-based solutions exist to
protect the confidentiality of data and the processing itself, such as
homomorphic encryption schemes, their performance is far from being practical
under real-world workloads.
The performance trade-offs of two novel hardware-assisted memory protection
mechanisms, namely AMD SEV and Intel SGX - currently available on the market to
tackle this problem, are described in this practical experience.
Specifically, we implement and evaluate a publish/subscribe use-case and
evaluate the impact of the memory protection mechanisms and the resulting
performance. This paper reports on the experience gained while building this
system, in particular when having to cope with the technical limitations
imposed by SEV and SGX.
Several trade-offs that provide valuable insights in terms of latency,
throughput, processing time and energy requirements are exhibited by means of
micro- and macro-benchmarks.Comment: European Commission Project: LEGaTO - Low Energy Toolset for
Heterogeneous Computing (EC-H2020-780681
Trusted Launch of Virtual Machine Instances in Public IaaS Environments
Cloud computing and Infrastructure-as-a-Service (IaaS) are emerging
and promising technologies, however their adoption is hampered by data security
concerns. At the same time, Trusted Computing (TC) is experiencing an increasing
interest as a security mechanism for IaaS. In this paper we present a protocol
to ensure the launch of a virtual machine (VM) instance on a trusted remote
compute host. Relying on Trusted Platform Module operations such as binding
and sealing to provide integrity guarantees for clients that require a trusted VM
launch, we have designed a trusted launch protocol for VM instances in public IaaS
environments. We also present a proof-of-concept implementation of the protocol
based on OpenStack, an open-source IaaS platform. The results provide a basis
for the use of TC mechanisms within IaaS platforms and pave the way for a wider
applicability of TC to IaaS security
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