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The process of determining whether a user is authorized to access a network.


An individual computer on a network that requests data from the network server.

Data Element

A single fact or figure (e.g., name, identification number) with accompanying information regarding the name, format, and definition of the piece of data.

Data Exchange Standard

An agreed upon format for facts and figures that is easily understood by all parties involved with the submission or receipt of data.

Data Exchange Template

A standardized format that identifies the types of information required or allowed in a particular document or exchange. Data exchange templates contain no data but instead define the format for exchange according to data standards and trading partner agreements.

Data Segment

A sequence of data elements (also see data element).

Data Standard

A documented agreement on the format and definition of common data

Digital Certificate

An electronic "identification card" which contains such information as the certificate holder's name and a serial number.

Digital Signature

An electronic version of a traditional signature that can be used as a means of identifying and authenticating documents sent and received electronically.

Document Type Definition (DTD)

A specific definition that accompanies a document and identifies how each markup (or tag) will be processed (also see markup, tag). Used in XML.


The process of converting data into a form or code that cannot be understood by unauthorized persons.

File Transfer Protocol (FTP)

A set of rules established for the exchange of files between computers. FTP is a common method of remote access that can be used via a dial-in or Internet connection. Either type of connection requires FTP software. FTP allows users to access files on the network and gives them the ability to delete, rename, transfer, or copy accessible files to and from that network.


A system implemented in both hardware and software, located at a network gateway server, that protects the resources of a private network from outside users.


A number generated by applying a mathematical formula to a document or sequence of text. The hash is significantly shorter that the original text and is unique to the original document.


A variable value created using a mathematical formula. Public keys are obtained from the certificate authority, while private keys are contained within each user's computer system (also see Public Key).


A description of data.


Any code or software that serves to combine two separate and existing programs.

Private Key

A mathematically-derived code provided by a certificate authority. The private key is stored in the user's computer and is not accessible to the public. It can be combined with the public key to encrypt and decrypt messages (also see PKI).


A set of communication rules used for data transfer.

Proxy Server

Hardware that is located between a client and a network server. Proxy servers filter requests that enter a network and improve performance by fulfilling small requests before they are sent to the network server.

Public Key

A mathematically-derived code provided by a certificate authority. The public key is stored in the digital certificate and can be combined with the private key to encrypt and decrypt messages (also see PKI and Digital Signature Fact Sheet).

Public Key Infrastructure (PKI)

A software application that allows users to encrypt and send information securely over a public network (also see encryption).


Database of information about source and target applications that includes data elements, inputs, processes, outputs, and relationships between applications.


A command inserted into a document's source code that specifies how the document, or a portion of the document, should be defined.

Trading Partner Agreement

A formal agreement between two parties for the purpose of defining the responsibilities of each party, the legalities of the proposed data exchange, and the technical details necessary to conduct the data exchange. TPAs are necessary when data exchange will be conducted without an intermediary and are intended to replace mandatory reporting requirements.

Virtual Private Network (VPN)

Using an existing public telecommunications infrastructure to create a private, secure data network.

Web Form

A standard interface that can be downloaded from the Internet. A Web form contains text boxes for a user to enter data. Users can then submit the form (e.g., environmental reports) to the receiver.


A flexible language for creating common information formats and sharing both the format and the data on the World Wide Web and elsewhere. XML, a formal recommendation from the World Wide Web Consortium (W3C), is similar to the language of today's Web pages, the Hypertext Markup Language (HTML).

For more information, see the World Wide Web Consortium Fact Sheet XML in 10 Points Exit EPA Disclaimer.

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