Region Delimited Coded Data Having Unique Length Digital Signature

• US 20090084859A1
• Filed: 11/25/2008
• Published: 04/02/2009
• Est. Priority Date: 05/18/2004
• Status: Active Grant

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul
• Granted Patent: US 7,793,854 B2
• Time in Patent Office: Days
• US Class Current: 235/494
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 20/105 involving programming of a portable memory device, e.g. IC cards, "electronic purses"
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 30/0185 Product, service or business identity fraud
• CPC Class Codes: G06Q 40/08 Insurance
• CPC Class Codes: G06Q 40/12 Accounting
• CPC Class Codes: G07D 7/004 using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Coded data for disposal on or in a surface is delimited into a number of regions. The coded data encodes an identity of the region in which the coded data is disposed, and a signature formed from at least part of the identity of the region and a substantially random number. The coded data is arranged in accordance with a layout having n-fold rotational symmetry, where n is at least two. The layout including n sub-layouts rotated 1/n revolutions apart about a centre of rotation, at least one sub-layout including rotation-indicating data that distinguishes that sub-layout from other sub-layouts. The random number serves as a padding to pad out the identity to a length unique to the identity.

Claims

1. Coded data for disposal on or in a surface, the coded data being delimited into a number of regions, the coded data encoding:

an identity of the region in which the coded data is disposed; and

a signature formed from at least part of the identity of the region and a substantially random number, wherein

the coded data is arranged in accordance with a layout having n-fold rotational symmetry, where n is at least two, the layout including n sub-layouts rotated 1/n revolutions apart about a centre of rotation, at least one sub-layout including rotation-indicating data that distinguishes that sub-layout from other sub-layouts, and

the random number serves as a padding to pad out the identity to a length unique to the identity.

2. Coded data according to claim 1, wherein the coded data includes a plurality of layouts, each layout defining the position of a plurality of first symbols encoding the identity, and a plurality of second symbols defining at least part of the signature.

5. Coded data according to claim 1, wherein the coded data is provided substantially coincident with visible human-readable information.

6. Coded data according to claim 1, wherein at least some of the coded data regions encode data indicative of at least one of:

a location of the respective data region, a position of the respective data region on the surface, a size of the data region, a size of the signature, an identity of a signature fragment, and units of indicated locations.

7. Coded data according to claim 1, wherein at least one coded data region further encodes at least a fragment of a data object.

8. Coded data according to claim 7, wherein the data object includes at least one of:

the signature, Multipurpose Internet Mail Extensions (MIME) data, text data, image data, audio data;

video data, application data, contact data, business card data, and directory data.

9. Coded data according to claim 1, wherein the coded data is adapted to be sensed by a sensing device to allow determination of the identity;

and, at least part of the signature.

3. Coded data according to claim 1, wherein the coded data is substantially invisible to an unaided human.

3-1. Coded data according to claim 4, wherein the coded data is printed on the surface using at least one of an invisible ink;

and an infrared-absorptive ink.