ELM Encryption Advance DDK Message (Tran Type 36-08)

Simplify supports an ELM Encryption Advance DDK message from the POS process.

The POS system can send Simplify an ELM Encryption Advance DDK request when the POS system wants to cause Simplify to have ELM advance to the next available DDK.

For a guide on when to use this command, please refer to the Verifone document:

Derived Key Merchant Implementation Overview

Care should be taken to ensure that this message is sent only once if responded to. Verifone states that there are 90 Derivation Keys configured in the PIN Pad. If the keys are changed every year, the keys should then last 90 years.

Before sending the ELM advance DDK message, please ensure that the Simplify PIN Pad has already registered with the Verifone VSP server. If the Simplify PIN Pad is able to process financial credit requests using the locator values (fields 109, 8002, 8006), then Advance DDK can be sent as long as the locator values do not change.

If an Advance DDK is sent with different values from those sent in the authorization requests, then the Simplify will register the PIN Pad to the VSP server without advancing to the next DDK.

The response for the Advance DDK will look like an approval message because Simplify will just echo a message sent by FuseBox for the Informational message. Whatever the response, please do not retry the advance DDK message as the PIN Pad has a limited number of DDK’s.

Sample Message

Request

An example of an ELM Encryption Advance DDK Request message (from the POS to Simplify) is:

Response

An example of an ELM Encryption Advance DDK Response message (from Simplify to the POS) is:

• previousLoad Simplify File via Secure File Transfer Message (Tran Type 36-07)
• nextELM Diagnostic Message (Tran Type 36-09)