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Obfuscation (software)
In software development, obfuscation is the act of creating source or machine code that is difficult for humans or computers to understand. Like obfuscation in natural language, it may use needlessly roundabout expressions to compose statements. Programmers may deliberately obfuscate code to conceal its purpose ( security through obscurity) or its logic or implicit values embedded in it, primarily, in order to prevent tampering, deter reverse engineering, or even to create a puzzle or recreational challenge for someone reading the source code. This can be done manually or by using an automated tool, the latter being the preferred technique in industry. Overview The architecture and characteristics of some languages may make them easier to obfuscate than others. C, C++, and the Perl programming language are some examples of languages easy to obfuscate. Haskell is also quite obfuscatable despite being quite different in structure. The properties that make a language obfus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Development
Software development is the process of conceiving, specifying, designing, programming, documenting, testing, and bug fixing involved in creating and maintaining applications, frameworks, or other software components. Software development involves writing and maintaining the source code, but in a broader sense, it includes all processes from the conception of the desired software through to the final manifestation of the software, typically in a planned and structured process. Software development also includes research, new development, prototyping, modification, reuse, re-engineering, maintenance, or any other activities that result in software products. Methodologies One system development methodology is not necessarily suitable for use by all projects. Each of the available methodologies are best suited to specific kinds of projects, based on various technical, organizational, project, and team considerations. Software development activities Identification of need The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Just Another Perl Hacker
Just another Perl hacker, or JAPH, typically refers to a Perl program that prints "Just another Perl hacker," (the comma is canonical but is occasionally omitted). Short JAPH programs are often used as signatures in online forums, or as T-shirt designs. The phrase or acronym is also occasionally used (without code) for a signature. JAPH programs are classically done using extremely obfuscated methods, in the spirit of the Obfuscated C Contest. More recently, as the phenomenon has become well-known, the phrase is sometimes used in ordinary examples (without obfuscation). The idea of using tiny Perl programs that print a signature ''as a signature'' was originated by Randal L. Schwartz, in his postings to the newsgroup comp.lang.perl. He wrote many of the JAPHs which are shown below. Examples JAPH program without obfuscation: print "Just another Perl hacker,"; Embedding JAPH in opaque code: $_='987;s/^(\d+)/$1-1/e;$1?eval:print"Just another Perl hacker,"';eval; Dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software License
A software license is a legal instrument (usually by way of contract law, with or without printed material) governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed. A typical software license grants the licensee, typically an end-user, permission to use one or more copies of software in ways where such a use would otherwise potentially constitute copyright infringement of the software owner's exclusive rights under copyright. Software licenses and copyright law Most distributed software can be categorized according to its license type (see table). Two common categories for software under cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, and the ability to modify, copy, share, and redistribute the work, with or without a fee. Licenses which implement copyleft can be used to maintain copyright conditions for works ranging from computer software, to documents, art, scientific discoveries and even certain patents. Copyleft software licenses are considered ''protective'' or ''reciprocal'' in contrast with permissive free software licenses, and require that information necessary for reproducing and modifying the work must be made available to recipients of the software program, which are often distributed as binary executables. This information is most commonly in the form of source code files, which usually contain a copy of the license terms and acknowledge the autho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source Software
Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2008 report by the Standish Group stated that adoption of open-source software models has resulted in savings of about $60 billion per year for consumers. Open source code can be used for studying and allows capable end users to adapt software to their personal needs in a similar way user scripts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AVG AntiVirus
AVG AntiVirus (previously known as AVG, an abbreviation of Anti-Virus Guard) is a line of antivirus software developed by AVG Technologies, a subsidiary of Avast, a part of Gen Digital. It is available for Windows, macOS and Android. History The brand AVG comes from Grisoft's first product, Anti-Virus Guard, launched in 1992 in the Czech Republic. In 1997, the first AVG licenses were sold in Germany and the UK. AVG was introduced in the US in 1998. The AVG Free Edition helped raise awareness of the AVG product line. In 2006, the AVG security package grew to include anti-spyware as AVG Technologies acquired ewido Networks, an anti-spyware group. AVG Technologies acquired Exploit Prevention Labs (XPL) in December 2007 and incorporated that company's LinkScanner safe search and surf technology into the AVG 8.0 security product range released in March 2008. In January 2009, AVG Technologies acquired Sana Security, a developer of identity theft prevention software. This softw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black-box Obfuscation
In cryptography, black-box obfuscation was a proposed cryptographic primitive which would allow a computer program to be obfuscated in a way such that it was impossible to determine anything about it except its input and output behavior. Black-box obfuscation has been proven to be impossible, even in principle. Impossibility The unobfuscatable programs Barak et al. constructed a family of unobfuscatable programs, for which an efficient attacker can always learn more from ''any'' obfuscated code than from black-box access. Broadly, they start by engineering a special pair of programs that cannot be obfuscated together. For some randomly selected strings \alpha, \beta of a fixed, pre-determined length k, define one program to be one that computes C_(x) := \begin \beta & \textx = \alpha\\ 0 & \text \end and the other program to one that computes D_(X) := \begin 1 & \textX(\alpha) = \beta\textX\text\leq\text(k)\\ 0 & \text \end. (Here, D_ interprets its input as the code for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indistinguishability Obfuscation
In cryptography, indistinguishability obfuscation (abbreviated IO or iO) is a type of software obfuscation with the defining property that obfuscating any two programs that compute the same mathematical function results in programs that cannot be distinguished from each other. Informally, such obfuscation hides the implementation of a program while still allowing users to run it. Formally, IO satisfies the property that obfuscations of two circuits of the same size which implement the same function are computationally indistinguishable. Indistinguishability obfuscation has several interesting theoretical properties. Firstly, iO is the "best-possible" obfuscation (in the sense that any secret about a program that can be hidden by any obfuscator at all can also be hidden by iO). Secondly, iO can be used to construct nearly the entire gamut of cryptographic primitives, including both mundane ones such as public-key cryptography and more exotic ones such as deniable encryption and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Man-in-the-middle Attack
In cryptography and computer security, a man-in-the-middle, monster-in-the-middle, machine-in-the-middle, monkey-in-the-middle, meddler-in-the-middle, manipulator-in-the-middle (MITM), person-in-the-middle (PITM) or adversary-in-the-middle (AiTM) attack is a cyberattack where the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other, as the attacker has inserted themselves between the two parties. One example of a MITM attack is active eavesdropping, in which the attacker makes independent connections with the victims and relays messages between them to make them believe they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker. The attacker must be able to intercept all relevant messages passing between the two victims and inject new ones. This is straightforward in many circumstances; for example, an attacker wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompiler
A decompiler is a computer program that translates an executable file to a high-level source file which can be recompiled successfully. It does therefore the opposite of a typical compiler, which translates a high-level language to a low-level language. Decompilers are usually unable to perfectly reconstruct the original source code, thus frequently will produce obfuscated code. Nonetheless, decompilers remain an important tool in the reverse engineering of computer software. Introduction The term ''decompiler'' is most commonly applied to a program which translates executable programs (the output from a compiler) into source code in a (relatively) high level language which, when compiled, will produce an executable whose behavior is the same as the original executable program. By comparison, a disassembler translates an executable program into assembly language (and an assembler could be used for assembling it back into an executable program). Decompilation is the act of usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abandonware
Abandonware is a product, typically software, ignored by its owner and manufacturer, and for which no official support is available. Within an intellectual rights contextual background, abandonware is a software (or hardware) sub-case of the general concept of '' orphan works''. Museums and various organizations dedicated to preserving this software continue to provide legal access. The term "abandonware" is broad, and encompasses many types of old software. Definitions of "abandoned" vary, but in general it is like any item that is abandoned – it is ignored by the owner, and as such product support and possibly copyright enforcement are also "abandoned". Types ;Commercial software unsupported but still owned by a viable company: The availability of the software depends on the company's attitude toward the software. In many cases, the company which owns the software rights may not be that which originated it, or may not recognize their ownership. Some companies, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
