Card Holder Unique Identifier

Overview
A Card Holder Unique Identifier (CHUID''') is a number stored electronically on a smart card comprising several pieces of data, including the federal agency smart credential number, global unique identifier, expiration date, and digital signature. These components are used to authenticate the card and ensure that the card has not expired. Visual authentication of the card’s security features and the photograph stored on the card are used to determine whether the card is genuine and whether it belongs to the individual using it.

Use of the CHUID combined with visual authentication provides more security assurance than visual authentication alone, because electronic means are used to authenticate the card. However, the CHUID is not encrypted, and thus there is some risk that a card may be forged.

Source

 * Government Accountability Office, Personal ID Verification: Agencies Should Set a Higher Priority on Using the Capabilities of Standardized Identification Cards 10 (GAO-11-751) (Sept. 2011) (full-text).