Obfuscation is the obscuring of the intended meaning of communication by making the message difficult to understand, usually with confusing and ambiguous language. The obfuscation might be either unintentional or intentional (although intent usually is connoted), and is accomplished with circumlocution (talking around the subject), the use of jargon (technical language of a profession), and the use of an argot (ingroup language) of limited communicative value to outsiders. 
In expository writing, unintentional obfuscation usually occurs in draft documents, at the beginning of composition; such obfuscation is illuminated with critical thinking and editorial revision, either by the writer or by an editor. Etymologically, the word obfuscation derives from the Latin obfuscatio, from obfuscāre (to darken); synonyms include the words beclouding and abstrusity.
Doctors are faulted for using jargon to conceal unpleasant facts from a patient; the American author and physician Michael Crichton said that medical writing is a "highly skilled, calculated attempt to confuse the reader". The psychologist B. F. Skinner said that medical notation is a form of multiple audience control, which allows the doctor to communicate to the pharmacist things which the patient might oppose if they could understand medical jargon. 
"Eschew obfuscation", also stated as "eschew obfuscation, espouse elucidation", is a humorous fumblerule used by English teachers and professors when lecturing about proper writing techniques. Literally, the phrase means "avoid being unclear" or "avoid being unclear, support being clear", but the use of relatively uncommon words causes confusion in much of the audience (those lacking the vocabulary), making the statement an example of irony, and more precisely a heterological phrase. The phrase has appeared in print at least as early as 1959, when it was used as a section heading in a NASA document. 
An earlier similar phrase appears in Mark Twain's Fenimore Cooper's Literary Offenses , where he lists rule fourteen of good writing as "eschew surplusage".
Obfuscation of oral or written communication achieves a degree of secure communication without a need to rely upon technology. This technique is sometimes referred to as "talking around" and is a form of security through obscurity.
A notable example of obfuscation of written communication is a message sent by September 11 attacks ringleader Mohamed Atta to other conspirators prior to the attacks occurring: 
The semester begins in three more weeks. We've obtained 19 confirmations for studies in the faculty of law, the faculty of urban planning, the faculty of fine arts and the faculty of engineering.
In this obfuscated message, the following code words are believed to exist: 
Within the illegal drug trade, obfuscation is commonly used in communication to hide the occurrence of drug trafficking. A common spoken example is "420", used as a code word for cannabis, a drug which, despite some recent prominent decriminalization changes, remains illegal in most places. The Drug Enforcement Administration reported in July 2018 a total of 353 different code words used for cannabis. 
In white-box cryptography, obfuscation refers to the protection of cryptographic keys from extraction when they are under the control of the adversary, e.g., as part of a DRM scheme. 
In network security, obfuscation refers to methods used to obscure an attack payload from inspection by network protection systems.
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication channel or storage in a storage medium. An early example is an invention of language, which enabled a person, through speech, to communicate what they thought, saw, heard, or felt to others. But speech limits the range of communication to the distance a voice can carry and limits the audience to those present when the speech is uttered. The invention of writing, which converted spoken language into visual symbols, extended the range of communication across space and time.
In cryptography, a cipher is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. To encipher or encode is to convert information into cipher or code. In common parlance, "cipher" is synonymous with "code", as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography.
Doublespeak is language that deliberately obscures, disguises, distorts, or reverses the meaning of words. Doublespeak may take the form of euphemisms, in which case it is primarily meant to make the truth sound more palatable. It may also refer to intentional ambiguity in language or to actual inversions of meaning. In such cases, doublespeak disguises the nature of the truth.
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decipher a ciphertext back to plaintext and access the original information. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor.
Gibberish, also called jibber-jabber or gobbledygook, is speech that is nonsense: ranging across speech sounds that are not actual words, pseudowords, language games and specialized jargon that seems nonsensical to outsiders.
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 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.
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a particular occupation, but any ingroup can have jargon. The main trait that distinguishes jargon from the rest of a language is special vocabulary—including some words specific to it and often different senses or meanings of words, that outgroups would tend to take in another sense—therefore misunderstanding that communication attempt. Jargon is sometimes understood as a form of technical slang and then distinguished from the official terminology used in a particular field of activity.
A codebook is a type of document used for gathering and storing cryptography codes. Originally codebooks were often literally books, but today codebook is a byword for the complete record of a series of codes, regardless of physical format.
A cant is the jargon or language of a group, often employed to exclude or mislead people outside the group. It may also be called a cryptolect, argot, pseudo-language, anti-language or secret language. Each term differs slightly in meaning; their uses are inconsistent.
In cryptology, a code is a method used to encrypt a message that operates at the level of meaning; that is, words or phrases are converted into something else. A code might transform "change" into "CVGDK" or "cocktail lounge". The U.S. National Security Agency defined a code as "A substitution cryptosystem in which the plaintext elements are primarily words, phrases, or sentences, and the code equivalents typically consist of letters or digits in otherwise meaningless combinations of identical length." A codebook is needed to encrypt, and decrypt the phrases or words.
The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography is a book by Simon Singh, published in 1999 by Fourth Estate and Doubleday.
The NCTE George Orwell Award for Distinguished Contribution to Honesty and Clarity in Public Language, is an award given since 1975 by the Public Language Award Committee of the National Council of Teachers of English. It is awarded annually to "writers who have made outstanding contributions to the critical analysis of public discourse."
A code word is a word or a phrase designed to convey a predetermined meaning to an audience who know the phrase, while remaining inconspicuous to the uninitiated. For example, a public address system may be used to make an announcement asking for "Inspector Sands" to attend a particular area, which staff will recognise as a code word for a fire or bomb threat, and the general public will ignore.
A wordfilter is a script typically used on Internet forums or chat rooms that automatically scans users' posts or comments as they are submitted and automatically changes or censors particular words or phrases.
Linguistic transparency is a phrase which is used in multiple, overlapping subjects in the fields of linguistics and the philosophy of language. It has both normative and descriptive senses.
Cryptography, or cryptology, 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 are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications.
The Doublespeak Award is an "ironic tribute to public speakers who have perpetuated language that is grossly deceptive, evasive, euphemistic, confusing, or self-centered", i.e. those who have engaged in doublespeak. It has been issued by the National Council of Teachers of English since 1974. Nominees must be from the US, though in 1975 the award was given to Yasser Arafat.
Jargon aphasia is a type of fluent aphasia in which an individual's speech is incomprehensible, but appears to make sense to the individual. Persons experiencing this condition will either replace a desired word with another that sounds or looks like the original one, or has some other connection to it, or they will replace it with random sounds. Accordingly, persons with jargon aphasia often use neologisms, and may perseverate if they try to replace the words they can not find with sounds.
Verbosity, or verboseness, is speech or writing that uses more words than necessary. The opposite of verbosity is plain language.
Humour in translation can be caused by translation errors, because of irregularities and discrepancies between certain items that translators attempt to translate. This could be due to the ignorance of the translator, as well as the untranslatability of the text as a result of linguistic or cultural differences. In addition, translation errors can be caused by the language incompetence of the translator in the target language, resulting in unintended ambiguity in the message conveyed. Translation errors can distort the intended meaning of the author or speaker, to the point of absurdity and ludicrousness, giving a humorous and comedic effect.