PURE CVM priority

Overview

PURE CVM selection is a negotiation between the digital wallet application and the terminal.

It determines the Cardholder Verification Method (CVM) used to authenticate the end user.

This page describes the CVM selection process based on the supported CVM options and the configured CVM priority.

CVM selection process

A PURE profile defines the supported CVMs and the CVM priority.

It uses the PURE application control field, byte 1 or byte 3:

• Byte 1 defines the CVM options associated with CIAC-CVM1.
• Byte 3 defines the CVM options associated with CIAC-CVM2.

NFC Wallet SDK requires the same CVM options for CIAC-CVM1 and CIAC-CVM2.

When a transaction requires CVM, the selection process chooses the first CVM supported by both the digital wallet application and the terminal.

The following parameters are used for CVM selection.

PURE application control details

The PURE application control field is a PURE profile value.

Bit mapping	Description
Byte 1 bit 6	1b: Local CDCVM is supported.
Byte 1 bit 4	1b: Signature is supported.
Byte 1 bit 3	1b: Online PIN is supported.
Byte 1 bit 1	1b: Online PIN is preferred over CDCVM. 0b: CDCVM is preferred over online PIN.

TTPI details

If the PURE profile supports TTPI (Terminal Transaction Processing Information), the terminal advertises its supported CVM capabilities through this field.

Bit mapping	Description
Byte 1 bit 3	Terminal capability: Support of Online PIN. 1 = Online PIN is supported. 0 = Online PIN is not supported.
Byte 1 bit 2	Terminal capability: Support of Signature. 1 = Signature is supported. 0 = Signature is not supported.
Byte 2 bit 7	Terminal request related to cardholder verification. 1 = CVM is required. 0 = CVM is not required.
Byte 3 bit 7	Terminal capability: Supports Consumer Device CVM as a possible CVM method when terminal requests for the cardholder verification in byte 2 bit 7. 1 = The terminal supports CDCVM as a possible CVM. 0 = Terminal does not consider CDCVM as a possible CVM.