Low-cost and Non-visual Labels Using Magnetic Printing

Abstract

This paper presents MagCode, a new type of barcode. MagCode label is printed with magnetic ink through ordinary printers and stores data in the magnetic field. By swiping a magnetometer over it, the stored data can be extracted. Thus, unlike ordinary barcodes, MagCode does not rely on visual channels to decode, implying untapped interaction opportunities when decoding ordinary visual code is not preferred or not possible. Its application cases include an unobstructed and low-cost input interface for wearables, whose visual sensing capabilities are usually limited. Further, MagCode's patterns can be designed to be visually-undecodable and our evaluation shows that accessing its magnetic signal requires very close approximation. These properties allow for using MagCode labels to convey covert and sensitive information, such as Easter eggs in games and payment credentials in daily life.