# US 2013/0254118 A1 · Decoding system coupled to a payment system that includes a cryptographic key > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0254118 A1 - Document ID: US20130254118A1 - Status: Published application - Kind: A1 - Application number: 13/829,209 - Filed: 2013-03-14 - Published: 2013-09-26 - Earliest claimed: 2010-10-13 - Assignees: Square, Inc. - Applicants: Square, Inc. - Inventors: Jack Dorsey; William Henderson; Brian Grassadonia; James M. McKelvey; Xuancong Wen - Web page: https://patentgrep.com/patent/US20130254118A1 ## CPC - G06Q 20/3227: {using secure elements embedded in M-devices} - G06Q 20/322: {Aspects of commerce using mobile devices [M-devices]} - G06Q 20/326: {Payment applications installed on the mobile devices} - G06Q 20/347: {Passive cards} - G06Q 20/40: Authorisation, e.g. identification of payer or payee, verification of customer or shop credentials; Review and approval of payers, e.g. check credit lines or negative lists - G06Q 30/06: Buying, selling or leasing transactions - G06Q 40/02: Banking, e.g. interest calculation or account maintenance (credit or loans G06Q40/03) - G07F 7/0886: {the card reader being portable for interacting with a POS or ECR in realizing a payment transaction} - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR - G07F: COIN-FREED OR LIKE APPARATUS (coin sorting G07D3/00; coin testing G07D5/00; {handling coins or paper currencies apart from payment activated apparatus G07D; payment architectures, schemes or protocols G06Q20/00}) ## Abstract A decoding system includes a decoding engine running on a mobile device that decodes signals produced from a read of a first party's financial transaction card. The decoding engine accepts and initializes incoming signals from a read of the first party's financial transaction card until the signals reach a steady state, detects the read once the incoming signals are in a steady state, identifies peaks in the incoming signals and digitizes the identified peaks in the incoming signals into bits. A transaction engine runs on the mobile device and is coupled to the decoding engine. The transaction engine receives as its input decoded first party's financial transaction card information from the decoding engine, and serves as an intermediary between the first party and a second party, so that the first party does not have to share his/her financial transaction card information with the second party. ## Claims ### Claim 1 A decoding system, comprising: a decoding engine running on a mobile device, the decoding engine in operation decoding signals produced from a read of a buyer's financial transaction card, the decoding engine in operation accepting and initializing incoming signals from a read of the buyer's financial transaction card until the signals reach a steady state, detecting the read of the buyer's financial transaction card once the incoming signals are in a steady state], identifying peaks in the incoming signals and digitizing the identified peaks in the incoming signals into bits; a transaction engine running on the mobile device and coupled to the decoding engine, the transaction engine in operation receiving as its input decoded buyer's financial transaction card information from the decoding engine and serving as an intermediary between the buyer and a merchant, so that the buyer does not have to share his/her financial transaction card information with the merchant; wherein the transaction engine is configured to be coupled to a payment service that sends a receipt to the buyer relative to the financial transaction. ### Claim 2 (depends on 1) The decoding system of claim 1 wherein the mobile device a mobile digital device. ### Claim 3 (depends on 1) The decoding system of claim 1 wherein the incoming signals are generated by swiping of the buyer's financial transaction card through a card reader configured to be coupled and de-coupled with the mobile device. ### Claim 4 (depends on 3) The decoding system of claim 3 wherein the incoming signals of low quality due to one or more of: low quality of data read from a single and/or low density track of a magnetic stripe of the card, sampling speed limitations of the mobile device, and noise introduced into the mobile device. ### Claim 5 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation detects presence of the read of the buyer's financial transaction card by looking for points in the incoming signals that exceed a minimum signal amplitude threshold. ### Claim 6 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation detects presence of the read of the buyer's financial transaction card by capturing signal of interest in the incoming signals via Fast Fourier Transform (FFT). ### Claim 7 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation detects peaks in the incoming signals to be resistant to ringing in the incoming signals. ### Claim 8 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation detects peaks in the incoming signals to be resistant to scratches in the card that cause slow quality or false peak information to manifest in the incoming signals. ### Claim 9 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation detects peaks in the incoming signals by looking for local maxima and minima within a window of digital samples. ### Claim 10 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation identifies the track from which data of the incoming signals are read through the read of the buyer's financial transaction card when only one track of data in a magnetic stripe of the buyer's financial transaction card is read. ### Claim 11 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation digitizes the identified peaks in the incoming signals into bits only by checking and comparing polarities of peaks. ### Claim 12 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation combines various peak detection and digitization approaches to cover various ranges of degradation in quality of the input signals read. ### Claim 13 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation chooses and optimizes different process combinations and parameters depending on hardware platform of the mobile device. ### Claim 14 (depends on 1) The decoding system of claim 1 wherein the decoding engine in operation scales and adjusts decoding to account for at least one of, different amounts of noise, sampling speed variations, signal ringing, and a swipe direction of the buyer's financial transaction card when the buyer's financial card is swiped through a slot of a card reader. ### Claim 15 (depends on 1) The decoding system of claim 1, wherein an output jack signal received by a card reader coupled to the mobile device is an encrypted output jack signal. ### Claim 16 (depends on 15) The decoding system of claim 15, wherein the output jack signal is an encrypted and signed output jack signal. ### Claim 17 (depends on 1) The decoding system of claim 1, wherein the card reader includes a front end with an amplifier/filter, differentiator and a comparator. ### Claim 18 (depends on 17) The decoding system of claim 17, wherein the front end further includes wake-up electronics. ### Claim 19 (depends on 18) The decoding system of claim 18, wherein the wake-up electronics is a wake-up circuit. ### Claim 20 (depends on 16) The decoding system of claim 16, wherein the output jack signal is a synchronous Manchester encoded stream.