Cleartext is a term used to describe text that has not been encrypted and does not require decryption in order to read. Sometimes used as an alternate term for plain text, cleartext actually has a distinct definition. Whereas plain text is a data between two parties that is in a language, computer or otherwise, that both know, cleartext is defined by the fact that it is never encrypted.
In order to protect and secure transmitted information, people use cryptography to disguise the message and make it only readable by those with a key, or decryption mechanism. While originally cryptography was done by hand, to put messages and letters in secret codes, today it is largely done using complex computer algorithms to provide high levels of security. Cleartext is data or messages that are not encrypted and were never meant to be encrypted, in contrast to plain text, which is the decoded form of encrypted text.
Cleartext may also refer to a document or file that uses a specific word processing program. Although these specific programs are a form of encryption, generally the data is not saved to that program as a means of protecting or securing it, but rather due to which word processor is conveniently installed. The intention of saving a text document in a word processing program is not to prevent others from seeing or reading it, therefore it is still considered cleartext.
Nearly any text program, word processor, or web browser can read cleartext. The search results and web pages that come up on a search engine are all examples of this type of document, since they can be read by anyone. If, however, a web page or document requires a person to sign in, enter a password, or use a certain program, it usually is subject to some form of encoding. Most email accounts use encryption to prevent anyone without a user name or password from reaching the data and decrypting it for reading. When the correct information is entered, the account automatically decrypts email information, making it readable.
It is important to remember that, when using cleartext, any person can view it. This means that security is nonexistent and the document, if posted on the internet can be viewed by any person, any where. Even slightly personal or private information should not be posted or sent in this manner. Posting or sending confidential information as cleartext, such as items that would violate confidentiality clauses, can result in legal action.