RFID Guardian Use-Cases Shopping

From RFID Wiki

In retail shops consumers could check out by rolling shopping carts past point-of-sale terminals. These terminals would automatically tally the items, compute the total cost, and perhaps even charge the consumer's RFID- enabled payment devices. RFID tags would act as indices into database payment records, and could also help retailers track defective or contami- nated items.

In this scenario the RFID reader is used for not only scanning goods but for payment transaction as well. In real life multi-standards readers are very common and they could serve in our example. But the contact- less smart card is just an option in this scenario and we will not include it in the UML diagram. We assume that multiple Guardians are within the proximity of the check-out desk and that is why mutual authentication is necessary here. The reader scans tags attached to the shop items and then transfers the tag ids back to the shop middleware. Then the shop middleware system will calculate the total price for these items and contact some payment systems, if necessary. At the end of a successful transaction, the middleware system will tell the reader to transfer the ownership of those items to RFID Guardian, so that the Guardian knows which tags it is going to protect.

UML Object Model

UML Sequence Model

With Sample ACL

################
# Shop Rules
################

context trusted;
context home;

# By default, we want to leave RFID traffic alone
rule P15693 ACCEPT
{
	context = *;
	role = *;
	tags = *;
	query = { command = *; };
};

# Deny other readers to read my credit card
rule P15693 DENY
{
	context = *;
	role = *;
	tags = @MY_TAGS;
	query = { command = *; };
};

# Only allow payment reader to read my card
rule P15693 ACCEPT
{
	context = {trusted, home, };
	role = LEGAL_READER;
	tags = @MY_CREDIT_CARD;
	query = { command = *; };
};