User's Manual

PIN Pad 791 Programmer’s Manual (PCI POS-A) UDN PM0103-U Rev. 06

Section 5 – Administration and maintenance messages 2015-04-20

Page39

Uniform Industrial Corp. Proprietary and Confidential Total 342 pages

Message 08 Select Master Key

Format: <SI>08[KeyID]<SO>[LRC]

Message length: Fixed 6 bytes.

Usage: This message is used to select one of the 10 possible PIN encrypting master keys

previously loaded using message 02. The selected master key will be used in the

following transactions.

Note: Check master key existence before change:

This message does not respond for checking master key existence. You may choose

an empty master key without notice.

TDES capability: If selected master key is a double length key (32 characters when

loaded with message 02), PP791 will treat all session keys (in MK/SK message 70,

Z60, Z62) as EDE encrypted by this master key. (See Appendix A)

Confirm key existence before issue 08: message 08 is not responsible for check if

[KeyID] has a valid master key, use message 04 before 08.

Message element:

Field Length Value and description

08 2 Message ID

[KeyID] 1 0~9, one of Master key id.

[LRC] 1 Checksum

Message flow:

HOST Direction PIN Pad

Message 08







[Success]

[Fail]

<SI>08[errCode]<SO>

<ACK>/<NAK>/

<EOT>





<EOT>

Error Message:

Error Code

Meaning

‘1’ Key index > 9