Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both hardware and software. Computing has scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology, and software engineering.
Computer programming or coding is the composition of sequences of instructions, called programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the application domain, details of programming languages and generic code libraries, specialized algorithms, and formal logic.
An integrated development environment (IDE) is a software application that provides comprehensive facilities for software development. An IDE normally consists of at least a source-code editor, build automation tools, and a debugger. Some IDEs, such as IntelliJ IDEA, Eclipse and Lazarus contain the necessary compiler, interpreter or both; others, such as SharpDevelop and NetBeans, do not.
In software development, obfuscation is the practice of creating source or machine code that is intentionally difficult for humans or computers to understand. Similar to obfuscation in natural language, code obfuscation may involve using unnecessarily roundabout ways to write statements. Programmers often obfuscate code to conceal its purpose, logic, or embedded values. The primary reasons for doing so are to prevent tampering, deter reverse engineering, or to create a puzzle or recreational challenge to deobfuscate the code, a challenge often included in crackmes. Whlie obfuscation can be done manually, it is more commonly performed using obfuscators.
Software cracking is an act of removing copy protection from a software. Copy protection can be removed by applying a specific crack. A crack can mean any tool that enables breaking software protection, a stolen product key, or guessed password. Cracking software generally involves circumventing licensing and usage restrictions on commercial software by illegal methods. These methods can include modifying code directly through disassembling and bit editing, sharing stolen product keys, or developing software to generate activation keys. Examples of cracks are: applying a patch or by creating reverse-engineered serial number generators known as keygens, thus bypassing software registration and payments or converting a trial/demo version of the software into fully-functioning software without paying for it. Software cracking contributes to the rise of online piracy where pirated software is distributed to end-users through filesharing sites like BitTorrent, One click hosting (OCH), or via Usenet downloads, or by downloading bundles of the original software with cracks or keygens.
A software bug is a design defect (bug) in computer software. A computer program with many or serious bugs may be described as buggy.
An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. In 2009, it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems.
A debugger is a computer program used to test and debug other programs. Common features of debuggers include the ability to run or halt the target program using breakpoints, step through code line by line, and display or modify the contents of memory, CPU registers, and stack frames.
A disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. The output of disassembly is typically formatted for human-readability rather than for input to an assembler, making disassemblers primarily a reverse-engineering tool. Common uses include analyzing the output of high-level programming language compilers and their optimizations, recovering source code when the original is lost, performing malware analysis, modifying software, and software cracking.
A key generator (key-gen) is a computer program that generates a product licensing key, such as a serial number, necessary to activate for use of a software application. Keygens may be legitimately distributed by software manufacturers for licensing software in commercial environments where software has been licensed in bulk for an entire site or enterprise, or they may be developed and distributed illegitimately in circumstances of copyright infringement or software piracy.
Software development is the process of designing and implementing a software solution to satisfy a user. The process is more encompassing than programming, writing code, in that it includes conceiving the goal, evaluating feasibility, analyzing requirements, design, testing and release. The process is part of software engineering which also includes organizational management, project management, configuration management and other aspects.
A patch is data that is intended to be used to modify an existing software resource such as a program or a file, often to fix bugs and security vulnerabilities. A patch may be created to improve functionality, usability, or performance. A patch is typically provided by a vendor for updating the software that they provide. A patch may be created manually, but commonly it is created via a tool that compares two versions of the resource and generates data that can be used to transform one to the other.
The Interactive Disassembler (IDA) is a disassembler for computer software which generates assembly language source code from machine-executable code. It supports a variety of executable formats for different processors and operating systems. It can also be used as a debugger for Windows PE, Mac OS X Mach-O, and Linux ELF executables. A decompiler plug-in, which generates a high level, C source code-like representation of the analysed program, is available at extra cost.
Hard coding is the software development practice of embedding data directly into the source code of a program or other executable object, as opposed to obtaining the data from external sources or generating it at runtime.
A UML tool is a software application that supports some or all of the notation and semantics associated with the Unified Modeling Language (UML), which is the industry standard general-purpose modeling language for software engineering.
Reversing: Secrets of Reverse Engineering is a textbook written by Eldad Eilam on the subject of reverse engineering software, mainly within a Microsoft Windows environment. It covers the use of debuggers and other low-level tools for working with binaries. Of particular interest is that it uses OllyDbg in examples, and is therefore one of the few practical, modern books on the subject that uses popular, real-world tools to facilitate learning. The book is designed for independent study and does not contain problem sets, but it is also used as a course book in some university classes.
Reverse engineering is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accomplishes a task with very little insight into exactly how it does so. Depending on the system under consideration and the technologies employed, the knowledge gained during reverse engineering can help with repurposing obsolete objects, doing security analysis, or learning how something works.
A decompiler is a computer program that translates an executable file back into high-level source code. Unlike a compiler, which converts high-level code into machine code, a decompiler performs the reverse process. While disassemblers translate executables into assembly language, decompilers go a step further by reconstructing the disassembly into higher-level languages like C. However, decompilers often cannot perfectly recreate the original source code and may produce obfuscated or less readable code.
In engineering, debugging is the process of finding the root cause, workarounds and possible fixes for bugs.
Anti-tamper software is software which makes it harder for an attacker to modify it. The measures involved can be passive such as obfuscation to make reverse engineering difficult or active tamper-detection techniques which aim to make a program malfunction or not operate at all if modified. It is essentially tamper resistance implemented in the software domain. It shares certain aspects but also differs from related technologies like copy protection and trusted hardware, though it is often used in combination with them. Anti-tampering technology typically makes the software somewhat larger and also has a performance impact. There are no provably secure software anti-tampering methods; thus, the field is an arms race between attackers and software anti-tampering technologies.
