Glossary

Message Digest

A message digest is a mathematical function that creates a fixed length data item, also known as a one-way hash, in a PDF document when it is digitally signed. Any tampering or changes in the document will result in a different message digest alerting Acrobat or the Reader that the document has been changed.

ISO 32000

Portable Document Format (PDF) is now ISO 32000-1:2008 based on the PDF Reference 1.7., an International Standard and a publication of the International Standards Organization (ISO). The document is managed by a democratically organized and open committee of subject matter experts through ISO’s Technical Committee TC 171, Administered by ANSI and AIIM. The official document may be purchased from the ISO website: ISO […]

Form Flattening

Form Flattening is a technique developed by Appligent in 2001; whereby, the data contained within a PDF form field is drawn directly to the page as page content; and, the original form field is removed from the document. PDF form fields; sometimes referred to as AcroForms, are a type of PDF annotation similar to hyperlinks […]

Form Field

A PDF form field is a type of “Widget” annotation whose purpose is to allow an end user to interactively enter data in a manner similar to filling in a paper based form. Following is the list of available field types: Text Button Check Box Radio Button Choice Signature Form fields within PDF are extensible; […]

Forms Data Format (FDF)

A Forms Data Format (FDF) file is a formatted ASCII file which contains key:value pairs defining the ﬁeld names and associated values that are used to populate a form. Forms Data Format (FDF) is defined in the international stand for Portable Document Format; ISO-32000. See ISO-32000-1:2008 Section 12.7.7. Following is an example of a simple FDF file: […]

Exemption Code

A word or group characters that indicates the reason for redacting a specific piece of information.

Encryption

“To alter (a file, for example) using a secret code so as to be unintelligible to unauthorized parties.” The American Heritage® Dictionary of the English Language, Fourth Edition, Copyright © 2000 by Houghton Mifflin Company. See Cipher.

Digital Signature

A digital signature is a process performed on a data stream that is based on the use of public key cryptography and cryptographic message digests. The purpose and function of a digital signature is twofold: Determine the data “signed” has not been altered Determine the person or entity who signed the data has been authenticated. […]

Digital Millennium Copyright Act (DMCA)

Title 1 of the United States Digital Millennium Copyright Act (DMCA) of 1998 restricts the legal use of software with respect to modifying encrypted documents. Appligent Document Solutions software will only permit the modification of encrypted documents when the owner password is supplied. Implementers should be aware that not all PDF modification software complies with the DMCA. […]

Cipher

A message written in secret code. or A secret method of writing. See Encryption.

Certified Mode

Certified mode is in Acrobat 8.0 and later. Certified mode is set in Acrobat Preferences, and insures that only Adobe-certified third-party plug-ins are loaded. This option is used only when there is reason to prevent third-party plug-ins to interact with your PDF documents.

Bookmarks

The Acrobat user interface uses the term “Bookmarks” for a collection of document placeholders. In the Acrobat user interface the Bookmarks are displayed in separate window pane located to the left side of the document window. Note: In the PDF Reference and ISO-32000; the term used is “Outlines”.

Bitmap Image

One of two major graphics types, also called a raster image. (The other type is a vector image). Bitmap graphics are made up of individual pixels or dots, each of which is assigned a color. Digital photographs and scanned images are examples of bitmap graphics.

Application Programming Interface (API)

A set of tools and/or calling conventions typically developed by a group which allows other programmers or advanced users to alter or enhance the capabilities of an application developed by the group. For example with regard to Acrobat, Adobe makes available an API for the C programming language which allows developers to build plug-ins for […]

Annotation

In PDF, an annotation is an item separate from the page content which is located in a layer above the page content. For example, like a Post-It® note is located over the text of a page. Annotations can take many forms. The following is a list of the most common annotations used in PDF: Markup […]

Advanced Encryption Standard (AES)

The Advanced Encryption Standard (AES) was adopted by the US National Institute of Standards and Technology (NIST) to replace the Data Encryption Standard (DES). With regard to PDF; Adobe added 128 bit AES to PDF 1.7; and, 256 bit AES to PDF 1.8.

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