57,495 research outputs found
A Verified Information-Flow Architecture
SAFE is a clean-slate design for a highly secure computer system, with
pervasive mechanisms for tracking and limiting information flows. At the lowest
level, the SAFE hardware supports fine-grained programmable tags, with
efficient and flexible propagation and combination of tags as instructions are
executed. The operating system virtualizes these generic facilities to present
an information-flow abstract machine that allows user programs to label
sensitive data with rich confidentiality policies. We present a formal,
machine-checked model of the key hardware and software mechanisms used to
dynamically control information flow in SAFE and an end-to-end proof of
noninterference for this model.
We use a refinement proof methodology to propagate the noninterference
property of the abstract machine down to the concrete machine level. We use an
intermediate layer in the refinement chain that factors out the details of the
information-flow control policy and devise a code generator for compiling such
information-flow policies into low-level monitor code. Finally, we verify the
correctness of this generator using a dedicated Hoare logic that abstracts from
low-level machine instructions into a reusable set of verified structured code
generators
Formal Computational Unlinkability Proofs of RFID Protocols
We set up a framework for the formal proofs of RFID protocols in the
computational model. We rely on the so-called computationally complete symbolic
attacker model. Our contributions are: i) To design (and prove sound) axioms
reflecting the properties of hash functions (Collision-Resistance, PRF); ii) To
formalize computational unlinkability in the model; iii) To illustrate the
method, providing the first formal proofs of unlinkability of RFID protocols,
in the computational model
Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services
Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing
efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings
Architecture and Design of Medical Processor Units for Medical Networks
This paper introduces analogical and deductive methodologies for the design
medical processor units (MPUs). From the study of evolution of numerous earlier
processors, we derive the basis for the architecture of MPUs. These specialized
processors perform unique medical functions encoded as medical operational
codes (mopcs). From a pragmatic perspective, MPUs function very close to CPUs.
Both processors have unique operation codes that command the hardware to
perform a distinct chain of subprocesses upon operands and generate a specific
result unique to the opcode and the operand(s). In medical environments, MPU
decodes the mopcs and executes a series of medical sub-processes and sends out
secondary commands to the medical machine. Whereas operands in a typical
computer system are numerical and logical entities, the operands in medical
machine are objects such as such as patients, blood samples, tissues, operating
rooms, medical staff, medical bills, patient payments, etc. We follow the
functional overlap between the two processes and evolve the design of medical
computer systems and networks.Comment: 17 page
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