scholarly journals On Time-sensitive Control Dependencies

2022 ◽  
Vol 44 (1) ◽  
pp. 1-37
Author(s):  
Martin Hecker ◽  
Simon Bischof ◽  
Gregor Snelting
Keyword(s):  
Execution Time ◽  
Efficient Algorithm ◽  
Reactive Systems ◽  
Efficient Algorithms ◽  
Control Flow ◽  
Efficient Computation ◽  
Performance Measurements ◽  
Flow Graphs

We present efficient algorithms for time-sensitive control dependencies (CDs). If statement y is time-sensitively control dependent on statement x , then x decides not only whether y is executed but also how many timesteps after x . If y is not standard control dependent on x , but time-sensitively control dependent, then y will always be executed after x , but the execution time between x and y varies. This allows us to discover, e.g., timing leaks in security-critical software. We systematically develop properties and algorithms for time-sensitive CDs, as well as for nontermination-sensitive CDs. These work not only for standard control flow graphs (CFGs) but also for CFGs lacking a unique exit node (e.g., reactive systems). We show that Cytron’s efficient algorithm for dominance frontiers [ 10 ] can be generalized to allow efficient computation not just of classical CDs but also of time-sensitive and nontermination-sensitive CDs. We then use time-sensitive CDs and time-sensitive slicing to discover cache timing leaks in an AES implementation. Performance measurements demonstrate scalability of the approach.

scholarly journals On the Automatic Analysis of the Practical Resistance of Obfusting Transformations

2019 ◽  
Vol 26 (3) ◽  
pp. 317-331 ◽  
Author(s):  
Petr D. Borisov ◽  
Yu. V. Kosolapov
Keyword(s):  
Execution Time ◽  
Hamming Distance ◽  
Symbolic Execution ◽  
Similarity Index ◽  
Control Flow ◽  
Control Flow Graph ◽  
Flow Graph ◽  
Similarity Indices ◽  
Program Characteristics ◽  
Flow Graphs

A method is developed for assessing the practical persistence of obfuscating transformations of programs based on the calculation of the similarity index for the original, obfuscated and deobfuscated programs. Candidates are proposed for similarity indices, which are based on such program characteristics as the control flow graph, symbolic execution time and degree of coverage for symbolic execution. The control flow graph is considered as the basis for building other candidates for program similarity indicators. On its basis, a new candidate is proposed for the similarity index, which, when calculated, finds the Hamming distance between the adjacency matrices of control flow graphs of compared programs. A scheme for estimating (analyzing) the persistence of obfuscating transformations is constructed, according to which for the original, obfuscated and deobfuscated programs, the characteristics of these programs are calculated and compared in accordance with the chosen comparison model. The developed scheme, in particular, is suitable for comparing programs based on similarity indices. This paper develops and implements one of the key units of the constructed scheme - a block for obtaining program characteristics compiled for the x86/x86 64 architecture. The developed unit allow to find the control flow graph, the time for symbolic execution and the degree of coverage for symbolic execution. Some results of work of the constructed block are given.

scholarly journals Generating Functionally Equivalent Programs Having Non-isomorphic Control-Flow Graphs

2017 ◽  
pp. 265-279 ◽  
Author(s):  
Rémi Géraud ◽  
Mirko Koscina ◽  
Paul Lenczner ◽  
David Naccache ◽  
David Saulpic
Keyword(s):  
Control Flow ◽  
Flow Graphs

A Unified Software Reengineering Approach towards Model Driven Architecture Environment

2011 ◽  
pp. 55-100
Author(s):  
Bing Qiao ◽  
Hongji Yang ◽  
Alan O’Callaghan
Keyword(s):  
Control Flow ◽  
Point Of View ◽  
Software System ◽  
Model Driven Architecture ◽  
Unified Framework ◽  
Software Reengineering ◽  
Model Driven ◽  
Incremental Development ◽  
Flow Graphs ◽  
And Control

When developing a software system, there are a number of principles, paradigms, and tools available to choose from. For a specific platform or programming language, a standard way can usually be found to archive the ultimate system; for example, a combination of an incremental development process, object-oriented analysis and design, and a well supported CASE (Computer-Aided Software Engineering) tool. Regardless of the technology to be adopted, the final outcome of the software development is always a working software system. However, when it comes to software reengineering, there is rather less consensus on either approaches or outcomes. Shall we use black-box or white-box reverse engineering for program understanding? Shall we produce data and control flow graphs, or some kind of formal specifications as the output of analysis? Each of these techniques has its pros and cons of tackling various software reengineering problems, and none of them on its own suffices to a whole reengineering project. A proper integration of various techniques capable of solving a specific issue could be an effective way to unravel a complicated software system. This kind of integration has to be done from an architectural point of view. One of the most exciting outcomes of recent efforts on software architecture is the Object Management Group’s (OMG) Model-Driven Architecture (MDA). MDA provides a unified framework for developing middleware-based modern distributed systems, and also a definite goal for software reengineering. This chapter presents a unified software reengineering methodology based on Model-Driven Architecture, which consists of a framework, a process, and related techniques.

Improving the K-Means Clustering Algorithm Oriented to Big Data Environments

2021 ◽  
pp. 289-308
Author(s):  
Joaquín Pérez Ortega ◽  
Nelva Nely Almanza Ortega ◽  
Andrea Vega Villalobos ◽  
Marco A. Aguirre L. ◽  
Crispín Zavala Díaz ◽  
...  
Keyword(s):  
Big Data ◽  
Text Mining ◽  
Large Volume ◽  
Execution Time ◽  
Clustering Algorithm ◽  
Efficient Algorithms ◽  
Experimental Results ◽  
Digital Format ◽  
Basic Approaches ◽  
Previous Iteration

In recent years, the amount of texts in natural language, in digital format, has had an impressive increase. To obtain useful information from a large volume of data, new specialized techniques and efficient algorithms are required. Text mining consists of extracting meaningful patterns from texts; one of the basic approaches is clustering. The most used clustering algorithm is k-means. This chapter proposes an improvement of the k-means algorithm in the convergence step; the process stops whenever the number of objects that change their assigned cluster in the current iteration is bigger than the ones that changed in the previous iteration. Experimental results showed a reduction in execution time up to 93%. It is remarkable that, in general, better results are obtained when the volume of the text increase, particularly in those texts within big data environments.

Generating Control Flow Graphs from NATURAL

2017 ◽  
pp. 395-402
Author(s):  
Strauss Cunha Carvalho ◽  
Renê Esteves Maria ◽  
Leonardo Schmitt ◽  
Luiz Alberto Vieira Dias
Keyword(s):  
Control Flow ◽  
Flow Graphs

Improving Similarity Measure for Java Programs Based on Optimal Matching of Control Flow Graphs

2015 ◽  
Vol 25 (07) ◽  
pp. 1171-1197 ◽  
Author(s):  
Dehong Qiu ◽  
Jialin Sun ◽  
Hao Li
Keyword(s):  
Graph Matching ◽  
Control Flow ◽  
Basic Block ◽  
New Approach ◽  
Java Program ◽  
Java Programs ◽  
Instruction Sequences ◽  
High Level ◽  
Flow Graphs ◽  
Basic Blocks

Measuring program similarity plays an important role in solving many problems in software engineering. However, because programs are instruction sequences with complex structures and semantic functions and furthermore, programs may be obfuscated deliberately through semantics-preserving transformations, measuring program similarity is a difficult task that has not been adequately addressed. In this paper, we propose a new approach to measuring Java program similarity. The approach first measures the low-level similarity between basic blocks according to the bytecode instruction sequences and the structural property of the basic blocks. Then, an error-tolerant graph matching algorithm that can combat structure transformations is used to match the Control Flow Graphs (CFG) based on the basic block similarity. The high-level similarity between Java programs is subsequently calculated on the matched pairs of the independent paths extracted from the optimal CFG matching. The proposed CFG-Match approach is compared with a string-based approach, a tree-based approach and a graph-based approach. Experimental results show that the CFG-Match approach is more accurate and robust against semantics-preserving transformations. The CFG-Match approach is used to detect Java program plagiarism. Experiments on the collection of benchmark program pairs collected from the students’ submission of project assignments demonstrate that the CFG-Match approach outperforms the comparative approaches in the detection of Java program plagiarism.

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