Cashier in the Supermarket Asking for Postal Code

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Cashier in the Supermarket Asking for Postal Code
Short Title Retailers Asking for Consumers Postal Code To Attribute What Shopping Baskets are Bought by a Particular Consumer
Location Global
Date October 2020

Solove Harm Aggregation, Interrogation, Identification
Information Preference, Transactional, Account, Demographic
Threat Actors Retailers

Affected Shoppers
High Risk Groups
Tangible Harms

Cashiers in the supermarkets often ask for postal code, when one pays using a credit card. This is retailers’ method to attribute shopping basket information to a uniquely identified shopper.


When a costumer is using a credit card, cashier often asks for the postal code. It happens because retailers want to attribute what shopping baskets are bought by a particular consumer.Aggregation The shop does not obtain all digits of peoples credit card number, but only a few last digits. As they are not unique enough, these digits don’t allow them to recognize each consumer.

But shops can gather some additional characteristics by simply asking consumers.Interrogation Postal code is nice, because its a short number, and customers generally don’t mind sharing it. Besides in a combination with digits of credit card is unique enough, which makes it an example of Identification. The digits of credit card and postal code together will often uniquely identify a particular customer and allow basket attribution. That way, retailers have a method to attribute which purchases are from one particular customer.


Threat: Retailers attributing shopping baskets information to consumers identity
At-Risk group: Supermarket customers
Harm: Aggregation
Secondary Consequences: not known

Threat: Cashier in the supermarket asking people for their postal code
At-Risk group: Supermarket customers
Harm: Interrogation
Secondary Consequences: not known

Threat: Retailers linking credit card last digits to the postal code to uniquely identify the customer
At-Risk group: Supermarket customers
Harm: Identification
Secondary Consequences: not known

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