3 research outputs found
A Touch of Evil: High-Assurance Cryptographic Hardware from Untrusted Components
The semiconductor industry is fully globalized and integrated circuits (ICs)
are commonly defined, designed and fabricated in different premises across the
world. This reduces production costs, but also exposes ICs to supply chain
attacks, where insiders introduce malicious circuitry into the final products.
Additionally, despite extensive post-fabrication testing, it is not uncommon
for ICs with subtle fabrication errors to make it into production systems.
While many systems may be able to tolerate a few byzantine components, this is
not the case for cryptographic hardware, storing and computing on confidential
data. For this reason, many error and backdoor detection techniques have been
proposed over the years. So far all attempts have been either quickly
circumvented, or come with unrealistically high manufacturing costs and
complexity.
This paper proposes Myst, a practical high-assurance architecture, that uses
commercial off-the-shelf (COTS) hardware, and provides strong security
guarantees, even in the presence of multiple malicious or faulty components.
The key idea is to combine protective-redundancy with modern threshold
cryptographic techniques to build a system tolerant to hardware trojans and
errors. To evaluate our design, we build a Hardware Security Module that
provides the highest level of assurance possible with COTS components.
Specifically, we employ more than a hundred COTS secure crypto-coprocessors,
verified to FIPS140-2 Level 4 tamper-resistance standards, and use them to
realize high-confidentiality random number generation, key derivation, public
key decryption and signing. Our experiments show a reasonable computational
overhead (less than 1% for both Decryption and Signing) and an exponential
increase in backdoor-tolerance as more ICs are added
XML security in XML data integrity, authentication, and confidentiality
The widely application of XML has increasingly required high security. XML security confronts some challenges that are strong relating to its features. XML data integrity needs to protect element location information and contextreferential meaning as well as data content integrity under fine-grained security situations. XML data authentication must satisfy a signing process under a dependent and independent multi-signature generation scenario. When several different sections are encrypted within the XML data, it cannot query the encrypted contents without decrypting the encrypted portions. The technologies relating to XML security demand further development. This thesis aims to improve XML security relative technologies, and make them more practicable and secure. A novel revocation information validation approach for X.509 certificate is proposed based on the XML digital signature technology. This approach reduces the complexity of XKMS or PKI systems because it eliminates the requirement for additional revocation checking from XKMS or CA. The communication burden between server and client could be alleviated. The thesis presents the context-referential integrity for XML data. An integrity solution for XML data is also proposed based on the concatenated hash function. The integrity model proposed not only ensures XML data content integrity, but also protects the structure integrity and elements’ context relationship within an XML data. If this model is integrated into XML signature technology, the signature cannot be copied to another document still keeping valid. A new series-parallel XML multi-signature scheme is proposed. The presented scheme is a mixed order specified XML multi-signature scheme according to a dependent and independent signing process. Using presented XML data integrity-checking pool to provide integrity-checking for decomposed XML data, it makes signing XPath expression practicable, rather than signing XML data itself. A new labeling scheme for encrypted XML data is presented to improve the efficiency of index information maintenance which is applied to support encrypted XML data query processing. The proposed labelling scheme makes maintenance index information more efficient, and it is easy to update XML data with decreasing the number of affected nodes to the lowest. In order to protect structural information for encrypted XML data, the encrypted nodes are removed from original XML data, and structural information is hidden. A case study is carried out to demonstrate how the proposed XML security relative approaches and schemes can be applied to satisfy fine-grained XML security in calibration certificate management.EThOS - Electronic Theses Online ServiceGBUnited Kingdo