Transaction Request Without a PIN

Command:

Validate the MAC on incoming data and return the MAC residue for subsequent processing.

Notes:

The command is used by the Acquirer for normal transaction message processing, and for Administration Request messages.

If the Host is unable to support binary data transfers, the command can be used in standard (ASCII character) asynchronous mode (in which the message containing the MAC is transferred in expanded hexadecimal notation).

Field

Length & Type

Details

COMMAND MESSAGE

Message header

m A

(Subsequently returned to the Host unchanged).

Command code

2 A

Value RE.

Terminal key

16 H

The terminal key encrypted under LMK pair 14-15.

AB

16 H

Formed in accordance with the terminal specification by the Host.

EITHER

For Binary Communications Modes:

Message length

3 H

X’001 to X’320 indicating the length of the next field.

Message text

n B

1 to 800 bytes of message. The last 64 bits (8 bytes) are the MAC field of which the left-most 32 bits contain the MAC.

OR

For Normal Async Modes:

Message length

3 H

X’002 to X’320 indicating the number of characters in the next field.

Message text

n H

2 to 800 hexadecimal characters representing 1 to 400 bytes of message. The last 16 characters contain the MAC field as above.

End message delimiter

1 C

Optional. Must be present if a message trailer is present. Value X’19.

Message trailer

n A

Optional. Maximum length 32 characters.

Field

Length & Type

Details

RESPONSE MESSAGE

Message header

n A

Response code

2 A

Error code

2 N

MAC residue

8 H

End message delimiter

1 C

Message trailer

n A