3DS ReferenceProtocol & field guide

EMV 3-D Secure · Core specification 2.3.1.1

Browser User Device IDdeviceId

Unique and immutable identifier linked to a device that is consistent across 3DS transactions for the specific user device. Examples: • Hardware Device ID • Platform-calculated device fingerprint Refer to D021 in the SDK Device Information

Read in message: AReq

Explore this field with transaction context

Message inclusion

Baseline inclusion. Effective requirements depend on transaction context. Check the field’s conditions and FAQ qualifications; select channel and category in the explorer.

MessageBaseline inclusion
AReqConditional

Conditional inclusion — source text

Required if available.

Format and scope

Type: String · Length: Variable, maximum 64 · Maximum length: 64

Source components
3DS Server
Device channels
02-BRW
Message categories
01-PA, 02-NPA

Version history

Field introduction tag: 2.3.1.1. Introduction tags are curated metadata, not a full history of changes. Compare versions and understand coverage.

Source and review status

EMV_3DS_CoreSpec_v2.3.1.1_20230530.pdf, Table A.1, PDF pages 215

Source review status: carried-forward. Carried-forward material has not acquired a new verification claim.

Source document fingerprint

EMV_3DS_CoreSpec_v2.3.1.1_20230530.pdf

6fdf0aba3fc1a765f96b74dad4069d1e189969f38f0023647021687daf589d6b

Official EMVCo specifications · Methodology and coverage limits