Timing Considerations Due To The Authentication Process; Support For File Compression - VeriFone VX 680 Reference Manual

P D
ERFORMING OWNLOADS
File Authentication Requirements
Timing
Considerations Due
to the
Authentication
Process
Support for File
Compression
96
VX 680 R
EFERENCE
•
When certificates are detected by the file authentication module of the
receiving terminal, they are processed exactly as in a direct download: All
certificates are checked one by one and, on authentication, are added to the
certificate tree of the receiving terminal. Then, all signature files are checked.
•
Downloaded certificates (receiving terminal) must synchronize with the
certificate data present in the certificate tree.
"Synchronized" means that the certificate tree of the receiving terminal can be
no more than one revision out-of-sync with the certificate tree on the sending
terminal or the files on the receiving terminal do not successfully authenticate.
In this case, the term revision refers to any generic change to the current
sponsor and signer certificates stored in the certificate tree of a deployment
terminal.
•
When the back-to-back download completes and all certificates and signature
files authenticate, the receiving terminal restarts. If the name of the *GO
application is specified in the Group 1 CONFIG.SYS file of the receiving
terminal, the application executes and the application prompt or logo is
displayed on the terminal.
The file authentication process takes some time. The total amount of time required
depends on a number of factors:
•
The number and size of application files.
•
The number of certificates and signature files.
•
Whether the file compression feature of Download Manager is being used to
perform the download.
Here are a few additional considerations that may affect the total elapsed time
required to complete the download operation:
•
Because additional processing steps are required, an operating system
download takes longer to complete than an application download (several
minutes as opposed to a few seconds).
•
The download order of a batch of certificate files may affect total processing
time. Digital certificates are validated in a looping process where the validation
process cycles as many times as necessary to establish the proper
relationship and position of a given certificate in the certificate tree that exists
in the terminal.
To optimize the authentication process, download certificates in a higher-level-
certificates-first order. This way, they process faster than a random order
download.
For information regarding file compression, refer to the Verix eVo Volume I:
Operating System Programmers Manual (VPN DOC00301).
G
UIDE