Chapter 4. Passbook, Apple’s digital wallet
This chapter covers
- Barcodes: the technology that makes Apple’s Passbook system possible
- Micro-documents as a convenient digital alternative to paper tickets and plastic cards
- Creating Passbook tickets with Ruby
- A method for validating Passbook tickets without a server
We have all come into contact with small documents that provide some benefit if we present them to the right person at the right time in the right location. Such documents include movie tickets that allow you to enter the movie theater, coupons that entitle you to receive a promotional discount for certain products, membership cards that let you enter the gym, loyalty cards for collecting loyalty points at the supermarket chain where you faithfully shop, or tickets for planes, trains, ships, or other vehicles providing transportation. Long before the digital revolution, those micro-documents were usually printed on paper with varying measures to prevent somebody from creating illicit copies.
Consider, for example, tickets for a sold-out concert. The concert organizer might go as far as embedding holograms in the paper the tickets are printed on to make sure that there’s no way for counterfeiters to produce their own tickets.