Fix Your Types

When using existing ACL2 datatype frameworks, many theorems require type hypotheses. These hypotheses slow down the theorem prover, are tedious to write, and are easy to forget. We describe a principled approach to types that provides strong type safety and execution efficiency while avoiding type hypotheses, and we present a library that automates this approach. Using this approach, types help you catch programming errors and then get out of the way of theorem proving.Comment: In Proceedings ACL2 2015, arXiv:1509.0552

Verified AIG Algorithms in ACL2

And-Inverter Graphs (AIGs) are a popular way to represent Boolean functions (like circuits). AIG simplification algorithms can dramatically reduce an AIG, and play an important role in modern hardware verification tools like equivalence checkers. In practice, these tricky algorithms are implemented with optimized C or C++ routines with no guarantee of correctness. Meanwhile, many interactive theorem provers can now employ SAT or SMT solvers to automatically solve finite goals, but no theorem prover makes use of these advanced, AIG-based approaches. We have developed two ways to represent AIGs within the ACL2 theorem prover. One representation, Hons-AIGs, is especially convenient to use and reason about. The other, Aignet, is the opposite; it is styled after modern AIG packages and allows for efficient algorithms. We have implemented functions for converting between these representations, random vector simulation, conversion to CNF, etc., and developed reasoning strategies for verifying these algorithms. Aside from these contributions towards verifying AIG algorithms, this work has an immediate, practical benefit for ACL2 users who are using GL to bit-blast finite ACL2 theorems: they can now optionally trust an off-the-shelf SAT solver to carry out the proof, instead of using the built-in BDD package. Looking to the future, it is a first step toward implementing verified AIG simplification algorithms that might further improve GL performance.Comment: In Proceedings ACL2 2013, arXiv:1304.712

Industrial-Strength Documentation for ACL2

The ACL2 theorem prover is a complex system. Its libraries are vast. Industrial verification efforts may extend this base with hundreds of thousands of lines of additional modeling tools, specifications, and proof scripts. High quality documentation is vital for teams that are working together on projects of this scale. We have developed XDOC, a flexible, scalable documentation tool for ACL2 that can incorporate the documentation for ACL2 itself, the Community Books, and an organization's internal formal verification projects, and which has many features that help to keep the resulting manuals up to date. Using this tool, we have produced a comprehensive, publicly available ACL2+Books Manual that brings better documentation to all ACL2 users. We have also developed an extended manual for use within Centaur Technology that extends the public manual to cover Centaur's internal books. We expect that other organizations using ACL2 will wish to develop similarly extended manuals.Comment: In Proceedings ACL2 2014, arXiv:1406.123

Solar Parking Lot Analysis: Smart Investment or Waste of Capital

In the last couple decades solar panels have been developed into a sustainable and effective method for harnessing clean energy. Today, solar panels have been engineered into solar roadways. Solar roadways are structurally engineered solar panels which can be installed in the Earth, driven on, and can replace the need for traditional asphalt roads. These solar roadways also include built in LEDs which mimic road lines and light up wildlife crossing the road, making these road panels a very safe alternative to traditional asphalt roads. This senior project is an analysis of solar roadways and their capabilities when applied to parking lots. It will specifically test how effective a solar parking lot will be when installed in the local San Luis Obispo Costco parking lot. In the end, a feasibility evaluation will determine if a solar parking lot will save more money than it costs. A critical literature review and energy analysis have been conducted to acquire the most important and relevant information to conclude whether solar parking lots could be the future. Industry professionals, who have many years of experience working with solar, and have shared their knowledge on this topic. The implementation of solar parking lots could effectively reverse energy consumption for businesses

Computed tomography measures of nutrition in patients with end-stage liver disease provide a novel approach to characterize deficits

Aim Patients with cirrhosis and end-stage liver disease (ESLD) develop severe nutrition deficits that impact on morbidity and mortality. Laboratory measures of nutrition fail to fully assess clinical deficits in muscle mass and fat stores. This study employs computed tomography imaging to assess muscle mass and subcutaneous and visceral fat stores in patients with ESLD. Methods This 1:1 case-control study design compares ESLD patients with healthy controls. Study patients were selected from a database of ESLD patients using a stratified method to assure a representative sample based on age, body mass index (BMI), gender, and model for end-stage liver disease score (MELD). Control patients were trauma patients with a low injury severity score (<10) who had a CT scan during evaluation. Cases and controls were matched for age +/- 5 years, gender, and BMI +/- 2. Results There were 90 subjects and 90 controls. ESLD patients had lower albumin levels (p<0.001), but similar total protein levels (p=0.72). ESLD patients had a deficit in muscle mass (-19%, p<0.001) and visceral fat (-13%, p<0.001), but similar subcutaneous fat (-1%, p=0.35). ESLD patients at highest risk for sarcopenia included those over age 60, BMI< 25.0, and female gender. We found degree of sarcopenia to be independent of MELD score. Conclusions These results support previous research demonstrating substantial nutrition deficits in ESLD patients that are not adequately measured by laboratory testing. Patients with ESLD have significant deficits of muscle and visceral fat stores, but a similar amount of subcutaneous fat

Graceful Degradation in IoT Security

As the consumer grade IoT devices industry advances, personal privacy is constantly eroded for the sake of convenience. Current security solutions, although available, ignore convenience by requiring the purchase of additional hardware, implementing confusing, out of scope updates for a non-technical user, or quarantining a device, rendering it useless. This paper proposes a solution that simultaneously maintains convenience and privacy, tailored for the Internet of Things. We propose a novel graceful degradation technique which targets individual device functionalities for acceptance or denial at the network level. When combined with current anomaly detection and fingerprinting methods, graceful degradation provides a personalized IoT security solution for the modern user

Invasion of the Botnet Snatchers: A Case Study in Applied Malware Cyberdeception

In this paper, we provide the initial steps towards a botnet deception mechanism, which we call 2face. 2face provides deception capabilities in both directions – upward, to the command and control (CnC) server, and downward, towards the botnet nodes – to provide administrators with the tools they need to discover and eradicate an infestation within their network without alerting the botnet owner that they have been discovered. The key to 2face is a set of mechanisms for rapidly reverse engineering the protocols used within a botnet. The resulting protocol descriptions can then be used with the 2face network deception tool to generate high-quality deceptive messaging, against the attacker. As context for our work, we show how 2face can be used to help reverse engineer and then generate deceptive traffic for the Mirai protocol. We also discuss how this work could be extended to address future threats