Digital watermarking systems

• US 7,111,168 B2
• Filed: 02/21/2001
• Issued: 09/19/2006
• Est. Priority Date: 05/01/2000
• Status: Expired due to Term

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: MacIntosh, Brian T., Seder, Phillip Andrew, Lofgren, Neil
• Primary Examiner(s): Cangialosi, Salvatore
• Application Number:
  US09/790,322
• Publication Number:
  US 20010037313A1
• Time in Patent Office: 2,036 Days
• Field of Search: 713/176, 380/34, 382/100
• US Class Current: 713/176
• CPC Class Codes: G06Q 20/12 specially adapted for electronic shopping systems
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3823 combining multiple encryption tools for a transaction
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 2201/3235 Checking or certification of the authentication information, e.g. by comparison with data stored independently

Abstract

A variety of systems responsive to watermarked documents are detailed. In one, watermarking is employed to facilitate secure online transactions. In another, a system for exchanging data is provided. One system includes a user terminal and a central site. The user terminal includes a watermark reader, and a capture device to capture an image of a watermarked document. The central site includes a database of image hashes. The user terminal communicates with the central site. The watermark reader reads a watermark and computes a hash of a captured image, and passes the hash to the central site for comparison with the database of image hashes.

Claims

1. A method of verifying data comprising;

digitally capturing an image;

computing a first hash of the captured image;

comparing the first hash with a database of hashes, the database of hashes comprising hashes corresponding to previously captured images; and

identifying an attack when the first hash matches at least one hash in the database.

2. The method of claim 1, further comprising:

enabling further processing when the first hash fails to match any of the hashes in the database.

3. A method of verifying data comprising:

digitally capturing an image;

computing a first hash of the captured image;

comparing the first hash with a database of hashes, the database of hashes comprising hashes corresponding to previously captured images, wherein the captured image comprises an embedded watermark,

extracting data from the watermark;

encrypting a request, the request comprising the extracted data and the first hash; and

sending the encrypted request to an external computer, wherein said comparing is performed at said external computer.

4. A method of verifying data comprising:

digitally capturing an image;

computing a first hash of the captured image;

comparing the first hash with a database of hashes, the database of hashes comprising hashes corresponding to previously captured images, wherein the captured image comprises an embedded plural-bit watermark,

extracting plural-bit date from the watermark;

encrypting a request comprising a block of image data from the image;

sending the encrypted request to an external computer;

wherein said computing and said comparing are performed at the external computer.

5. A system for exchanging data comprising:

a user terminal comprising a watermark reader, and a capturing device to capture an image of a watermarked document; and

a central site comprising a database of image hashes, wherein said user terminal communicates with said central site, and wherein said reader reads a watermark and computes a hash of a captured image and passes the hash to said central site for comparison with said database of image hashes.

6. A method of preventing online attacks, comprising:

capturing an encoded image;

extracting data from the encoded image;

computing a hash of the captured image;

comparing the hash against previously determined hashes; and

linking the extracted data to other data when the hash does not match any of the previously determined hashes.

7. A method of preventing online attacks, comprising:

capturing an encoded image;

extracting data from the encoded image;

computing a hash of the captured image;

comparing the hash against previously determined hashes; and

disregarding the extracted data when the hash matches at least one of the previously determined hashes.

8. A method comprising:

maintaining a database including a plurality of hashes stored therein;

receiving through a network a first hash derived from image data, the first hash being derived remotely relative to performance of said method;

determining whether the first hash has been previously received with reference to at least the plurality of hashes stored in the database;

disregarding a request associated with the first hash if the first hash has been previously received.

9. A method comprising:

maintaining a database including a plurality of hashes stored therein;

receiving through a network a request and a first hash derived from image data, the first hash being derived remotely relative to performance of said method;

determining whether the first hash has been previously received with reference to at least the plurality of hashes stored in the database;

as a condition of executing the request, requesting validation information from a user associated with the request when the first hash has been previously received; and

executing the request when at least one of the following is met;

i) the first hash has not been previously received; and

ii) proper validation information is received from a user.