User's Manual

FILE AUTHENTICATION
Introduction to File Authentication
VX 675 R
EFERENCE GUIDE 83
Authentication Requirements for Specific File Types
For the purposes of file authentication, executable code files include two file types
that can be recognized by the filename extensions listed in Table 8.
Depending on the logical security requirements of specific applications, other
types of files used by an application (that is, non-executable files) must also be
authenticated.
• Data files (*.dat) that contain sensitive customer information or other data
that must be secure
• Font files (*.vft or *.fon) may need to be secure to prevent unauthorized
text or messages from being displayed on the terminal screen.
• Any other type of file used by an application in which the application designer
would like to logically secure using file authentication requirements
Decide Which Files to Authenticate in a Specific Application
The first step in the file authentication process is to determine which files must be
authenticated for an application to meet its design specifications for logical
security under the VeriShield Retain security architecture.
In most cases, application designers make these decisions based on
specifications provided by the terminal sponsor. Determining which files to
authenticate can be completely transparent to the person or business entity
responsible for signing, downloading, and authenticating an application prior to
deployment.
How (and When) Signature Files Authenticate Their Target Files
Signature files are usually downloaded together with their target application files in
the same data transfer operation. This recommended practice lets you specify
and confirm the logical security status of the VX 675 terminal each time you
perform an application download.
When the file authentication module detects a new signature file after a terminal
restart, it locates and attempts to authenticate the target file that corresponds to
the new signature file.
Table 8 Executable File Extensions
File Type Extension
Compiled and linked application files *.out
Global function libraries *.lib