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Mitigating Power Side Channels during Compilation [article]

Jingbo Wang and Chungha Sung and Chao Wang
2019 arXiv   pre-print
The code generation modules inside modern compilers such as GCC and LLVM, which use a limited number of CPU registers to store a large number of program variables, may introduce side-channel leaks even in software equipped with state-of-the-art countermeasures. We propose a program analysis and transformation based method to eliminate this side channel. Our method has a type-based technique for detecting leaks, which leverages Datalog-based declarative analysis and domain-specific optimizations
more » ... to achieve high efficiency and accuracy. It also has a mitigation technique for the compiler's backend, more specifically the register allocation modules, to ensure that potentially leaky intermediate computation results are always stored in different CPU registers or spilled to memory with isolation. We have implemented and evaluated our method in LLVM for the x86 instruction set architecture. Our experiments on cryptographic software show that the method is effective in removing the side channel while being efficient, i.e., our mitigated code is more compact and runs faster than code mitigated using state-of-the-art techniques.
arXiv:1902.09099v1 fatcat:fbhbcmej4fbjtpegu2xg3yxdaq

Modular Verification of Interrupt-Driven Software [article]

Chungha Sung, Markus Kusano, Chao Wang
2017 arXiv   pre-print
[35] Chungha Sung, Markus Kusano, Nishant Sinha, and Chao Wang.  ...  Modular Verification of Interrupt-Driven Software Chungha Sung Markus Kusano  ... 
arXiv:1709.10078v1 fatcat:evmt3tlum5e2nlyhyn5vcyiz4i

CANAL: A Cache Timing Analysis Framework via LLVM Transformation [article]

Chungha Sung and Brandon Paulsen and Chao Wang
2018 arXiv   pre-print
A unified modeling framework for non-functional properties of a program is essential for research in software analysis and verification, since it reduces burdens on individual researchers to implement new approaches and compare existing approaches. We present CANAL, a framework that models the cache behaviors of a program by transforming its intermediate representation in the LLVM compiler. CANAL inserts auxiliary variables and instructions over these variables, to allow standard verification
more » ... ols to handle a new class of cache related properties, e.g., for computing the worst-case execution time and detecting side-channel leaks. We demonstrate the effectiveness of CANAL using three verification tools: KLEE, SMACK and Crab-llvm. We confirm the accuracy of our cache model by comparing with CPU cycle-accurate simulation results of GEM5. CANAL is available on GitHub and YouTube.
arXiv:1807.03329v1 fatcat:n5y3s2aybzhwxi6wmyohyyawii

Debreach: Mitigating Compression Side Channels via Static Analysis and Transformation [article]

Brandon Paulsen, Chungha Sung, Peter A.H. Peterson, Chao Wang
2019 arXiv   pre-print
Sung et al. used it to improve automated testing of JavaScript-based web applications [60] and semantic diffing of concurrent programs [61] .  ... 
arXiv:1909.05977v1 fatcat:oxxmbaz2mrcibl4jj6pygbdx7m

Datalog-based Scalable Semantic Diffing of Concurrent Programs [article]

Chungha Sung and Shuvendu Lahiri and Constantin Enea and Chao Wang
2018 arXiv   pre-print
When an evolving program is modified to address issues related to thread synchronization, there is a need to confirm the change is correct, i.e., it does not introduce unexpected behavior. However, manually comparing two programs to identify the semantic difference is labor intensive and error prone, whereas techniques based on model checking are computationally expensive. To fill the gap, we develop a fast and approximate static analysis for computing synchronization differences of two
more » ... . The method is fast because, instead of relying on heavy-weight model checking techniques, it leverages a polynomial-time Datalog-based program analysis framework to compute differentiating data-flow edges, i.e., edges allowed by one program but not the other. Although approximation is used our method is sufficiently accurate due to careful design of the Datalog inference rules and iterative increase of the required data-flow edges for representing a difference. We have implemented our method and evaluated it on a large number of multithreaded C programs to confirm its ability to produce, often within seconds, the same differences obtained by human; in contrast, prior techniques based on model checking take minutes or even hours and thus can be 10x to 1000x slower.
arXiv:1807.03777v2 fatcat:ilsv273jbjbp3k5zuqidjzviha

Static DOM event dependency analysis for testing web applications

Chungha Sung, Markus Kusano, Nishant Sinha, Chao Wang
2016 Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering - FSE 2016  
The number and complexity of JavaScript-based web applications are rapidly increasing, but methods and tools for automatically testing them are lagging behind, primarily due to the difficulty in analyzing the subtle interactions between the applications and the event-driven execution environment. Although static analysis techniques have been routinely used on software written in traditional programming languages, such as Java and C++, adapting them to handle JavaScript code and the HTML DOM is
more » ... ifficult. In this work, we propose the first constraint-based declarative program analysis procedure for computing dependencies over program variables as well as event-handler functions of the various DOM elements, which is crucial for analyzing the behavior of a client-side web application. We implemented the method in a software tool named JSDEP and evaluated it in ARTEMIS, a platform for automated web application testing. Our experiments on a large set of web applications show the new method can significantly reduce the number of redundant test sequences and significantly increase test coverage with minimal overhead.
doi:10.1145/2950290.2950292 dblp:conf/sigsoft/SungKS016 fatcat:nhngcwrlizdrblam4f5iba76qq

Use of Bacteria to Activate Ground-Granulated Blast-Furnace Slag (GGBFS) as Cementless Binder

Woo Sung Yum, Jinung Do
2022 Materials  
Materials and Methods GGBFS Commercial GGBFS was used in this study (Chunghae material Co., Ltd., yang, Korea).  ...  Materials and Methods GGBFS Commercial GGBFS was used in this study (Chunghae material Co., Ltd., Gwangyang, Korea).  ... 
doi:10.3390/ma15103620 pmid:35629646 fatcat:f4lz6lwvjjcdzfda2v2errzaum

Local Arrangement Chairs & Webmasters Publication Chair Steering Committee Program Committee Additional Reviewers

Sean Safarpour, Synopsys Divjyot, Sethi Cisco, Jens Katelaan, Keshav Kini, Florian Zuleger, Armin Biere, Alan Hu, Warren Hunt, Vigyan Singhal, Oski Tech, Pranav Real (+126 others)
Proceedings of the 16th Conference on Formal Methods in Computer-Aided Design (FMCAD 2016)   unpublished
The International Conference on Formal Methods in Computer-Aided Design (FMCAD) is a series of meetings presenting groundbreaking results on the theory and application of rigorous formal techniques for the automated design of systems. The FMCAD conference covers the entire spectrum of formal aspects of specification, verification, synthesis, and testing, and is a leading forum for researchers and practitioners in academia and industry alike. The sixteenth meeting in the series was held in
more » ... in View, California, USA, October 3-6, 2016. FMCAD 2016 featured a high quality program comprised of five parts: a memorial session for Professor Helmut Veith, one of the original co-chairs for this event, a tutorial day with four tutorials, a series of invited talks by experts in areas adjoining formal methods, a student forum, and finally the main program consisting of the accepted papers. Before his unexpected passing, Helmut Veith was one of the key persons in shaping this event. We have endeavored to stay true to his vision by creating a program that is informative, high quality, and enjoyable at the same time. We had a memorial session for Helmut with talks by his collaborators and friends. This was a followed by a keynote by Professor Christos Papadimitriou on algorithms and evolution. Helmut was excited about having this talk at FMCAD and we were glad that Professor Papadimitriou was able to give this talk. This year FMCAD featured exciting keynote talks not just from formal methods, but also from adjoining areas: • Formal Verification for Computer Security: Lessons Learned and Future Directions by Dawn Song (UC Berkeley) • Understanding Evolution through Algorithms by Christos Papadimitriou (UC Berkeley) • Network Verification -When Clarke Meets Cerf by George Varghese (UCLA) All these talks were given by well known experts, possibly outside the traditional topics at FMCAD, but were crucial for expanding horizons of the formal methods community. The talk on evolution, in particular, was not connected to formal methods, but we honored Helmut's wish to have a fun invited talk on the latest advances in the broader field of Computer Science. The tutorial day featured four tutorials, given below in the order of presentation. These gave the audience both a look into the latest developments in the field, and a retrospective on formal methods in the industry. • Machine Learning and Systems for the Next Frontier in Formal Verification by Manish Pandey, Synopsys Inc. • Verifying Hyperproperties of Hardware Systems by Bernd Finkbeiner (Saarland University) and Markus Rabe (UC Berkeley) • A Paradigm Shift in Verification Methodology by Pranav Ashar (RealIntent) • Program Synthesis for Networks by Pavol Černý (University of Colorado Boulder) FMCAD also offered the fourth edition of the Student Forum, organized by Hossein Hojjat (Rochester Institute of Technology). The Forum is described in more detail later in these proceedings. For the main program, we received 64 submissions, resulting in 23 high quality accepted papers. Each paper was reviewed by at least four reviewers. The authors were then given the opportunity to respond to the comments and correct any misunderstanding. This rebuttal phase lasted a week and was followed by discussions among the reviewers to converge on a final score for the paper. The final set of accepted papers ranged from protocol verification, architectural specification capture, traditional hardware, software verification, SMT solvers, program synthesis, and verification of timed systems. During the conference each paper was presented by one of the authors followed by a brief Q&A. Each regular paper was allotted 30 minutes and the three short papers were allotted 15 minutes each. A conference with such a diverse program and audience as FMCAD relies on a large number of people supporting the organization. The program committee members are too numerous to list individually; we thank each and every one of them for their time, dedication to the purpose of FMCAD, their willingness to help the authors improve their manuscripts, and their help with additional tasks such as selecting and reviewing papers for the Best Paper Award. Our sincere gratitude further goes out to the Publication Chair Florian Zuleger (Vienna University of Technology, Austria; in charge of these proceedings). Hossein Hojjat (Rochester Institute of Technology) took over the non-trivial task of serving as Student Forum Chair; his engagement and enthusiasm for the process ensured an encouragingly large number of Student Forum submissions. Special thanks goes to Jens Katelaan (Vienna University of Technology, Austria) and Keshav Kini (University of Texas at Austin) formally the Webchairs, creating and maintaining a snappy new FMCAD website. The conference would not be possible without the tireless efforts of our Local Chairs Sean Safarpour (Synopsys) and Divjyot Sethi (Cisco) who made all the arrangements for conference to take place. Sean in particular worked with Synopsys management to host FMCAD at its facilities and ultimately save us quite a bit of expenses. As always, the FMCAD Steering Committee was available with both guidance and encouragement whenever needed, and even when not. We thank Armin Biere
fatcat:6gmwf4yr6zbvzomhwj7atm6gq4

Static Race Detection for RTOS Applications [article]

Rishi Tulsyan, Rekha Pai, Deepak D'Souza
2020 arXiv   pre-print
create(A, p, t) Technical Conference, pages 97-106, 1993. 26 Chungha Sung, Markus Kusano, and Chao Wang. Modular verification of interrupt-driven software.  ...  Sung et al. [26] propose a modular technique for static verification of interrupt-driven programs with nesting and priorities.  ... 
arXiv:2010.02642v1 fatcat:qvvxfxsqmffibcmrkze3onszom

Use of Coal Bottom Ash and CaO-CaCl2-Activated GGBFS Binder in the Manufacturing of Artificial Fine Aggregates through Cold-Bonded Pelletization

Dongho Jeon, Woo Sung Yum, Haemin Song, Seyoon Yoon, Younghoon Bae, Jae Eun Oh
2020 Materials  
Commercial GGBFS (Chunghae, Korea) was used. Analytical grade CaO and CaCl 2 (extra pure, 98%) were used as activators.  ... 
doi:10.3390/ma13245598 pmid:33302516 fatcat:wultfgxhrrennntbuciyewh7r4

Changes on CRAN

Kurt Hornik, Achim Zeileis
2013 The R Journal   unpublished
Authors: ChungHa Sung, TaeJoon Song, Jae W. Lee, and Junghoon Lee. Authors: Austin Chungath Vincent, Sachin Sudarshana, Vikas Raguttahalli. RND Risk Neutral Density. Author: Kam Hamidieh.  ... 
fatcat:urylsmqzejfj3jmazwjbivwsny

Traditional scholar-officials on the wings of modern law and statecraft : the Taedong hakhoe and its vision for the Korean ruling class in the final years of the Taehan Empire, 1907-1909

Young Woo Park
2019
things and affairs, if they deviated from 141 I have borrowed the term "This Culture of Ours" as a translation for samun 斯文 from PeterBol, This Culture of Ours: Intellectual Transitions in T'ang and Sung  ...  . -1919 r. 1897 -1907 abdication, is a request signed by several top figures-Sin Kisŏn, Sŏ Chŏngsun, Min Pyŏngsŏk, Yi Yongjik, Kim Hakchin, Nam Chŏngch'ŏl, Yi Chungha, and Hong Sŭngmok-of the Taedong  ... 
doi:10.14288/1.0375875 fatcat:5ybjmtsopjcb5g2mj3f3yeefry