Detecting misuse of trusted seals

1. A computer-implemented method of detecting misuse of a trusted seal by a website having a plurality of images, the method comprising:

using a computer processor to perform steps comprising:

detecting that a larger image of the website contains a plurality of smaller images;

extracting the plurality of smaller images from the larger image;

determining whether spatial dimensions of the plurality of extracted smaller images are similar to spatial dimensions of images of trusted seals issued by known trusted parties to websites certified as using appropriate security procedures;

selecting at least one extracted image of the website for comparison responsive to spatial dimensions of the selected image being similar to spatial dimensions of an image of a trusted seal;

comparing the selected image of the website to the image of the trusted seal to determine a perceptual distance between the selected image and the image of the trusted seal;

responsive to the comparison indicating that the selected image of the website matches the image of the trusted seal based on the determined perceptual distance, verifying that the website is authorized to use the trusted seal; and

responsive to the verification indicating that the website is not authorized to use the trusted seal, reporting that the website is misusing the trusted seal.

2. The method of claim 1 , further comprising:

determining a reputation associated with the website, the reputation indicating trustworthiness of the website;

wherein the determining, selecting, comparing, verifying, and reporting steps are performed responsive to the reputation indicating that the website is untrustworthy.

3. The method of claim 2 , wherein determining the reputation associated with the website comprises:

providing an identifier of the website to a security server, the security server adapted to provide the reputation of the website responsive to receiving the identifier.

4. The method of claim 1 , wherein the comparing comprises:

generating a perceptual hash value of the selected image of the website;

comparing the perceptual hash value of the selected image with a perceptual hash value generated from the image of the trusted seal to determine the perceptual distance between the selected image and the image of the trusted seal; and

determining that the selected image of the website matches the image of the trusted seal responsive to the perceptual distance.

5. The method of claim 4 , wherein determining the perceptual distance between the selected image and the image of the trusted seal comprises:

calculating a Hamming distance between the perceptual hash value of the selected image and the perceptual hash value of the image of the trusted seal.

6. The method of claim 1 , wherein verifying that the website is authorized to use the trusted seal comprises:

providing an identifier of the website to a verification server, the verification server using the identifier to determine whether the website is authorized to use the trusted seal.

7. The method of claim 1 , further comprising:

identifying a home page of a plurality of pages of the website; and

detecting a plurality of images contained in the home page of the website;

wherein the determining determines whether spatial dimensions of only the plurality of images contained in the home page of the website are similar to spatial dimensions of images of trusted seals.

8. The method of claim 1 , further comprising:

identifying a subset of pages of a plurality of web pages of the website that collect personally-identifiable information; and

detecting a plurality of images contained in the identified subset of pages that collect personally-identifiable information;

wherein the determining determines whether spatial dimensions of only the plurality of images contained in the identified subset of pages are similar to spatial dimensions of images of trusted seals.

9. A non-transitory computer-readable storage medium storing executable computer program instructions for detecting misuse of a trusted seal by a website having a plurality of images on a plurality of web pages, the computer program instructions comprising instructions for:

detecting that a larger image of the website contains a plurality of smaller images;

extracting the plurality of smaller images from the larger image;

determining whether spatial dimensions of the plurality of extracted smaller images are similar to spatial dimensions of images of trusted seals issued by known trusted parties to websites certified as using appropriate security procedures;

selecting at least one extracted image of the website for comparison responsive to spatial dimensions of the selected image being similar to spatial dimensions of an image of a trusted seal;

comparing the selected image to the image of the trusted seal to determine a perceptual distance between the selected image and the image of the trusted seal;

responsive to the comparison indicating that the selected image of the website matches the image of the trusted seal based on the determined perceptual distance, verifying that the website is authorized to use the trusted seal; and

responsive to the verification indicating that the website is not authorized to use the trusted seal, reporting that the website is misusing the trusted seal.

10. The computer-readable storage medium of claim 9 , further comprising instructions for:

determining a reputation associated with the website, the reputation indicating trustworthiness of the website;

wherein the determining, selecting, comparing, verifying, and reporting steps are performed responsive to the reputation indicating that the website is untrustworthy.

11. The computer-readable storage medium of claim 10 , wherein the computer program instructions for determining the reputation associated with the website further comprise instructions for:

providing an identifier of the website to a security server, the security server adapted to provide the reputation of the website responsive to receiving the identifier.

12. The computer-readable storage medium of claim 9 , wherein the computer program instructions for comparing further comprise instructions for:

generating a perceptual hash value of the selected image of the website;

comparing the perceptual hash value of the selected image with a perceptual hash value generated from the image of the trusted seal to determine the perceptual distance between the selected image and the image of the trusted seal; and

determining that the selected image of the website matches the image of the trusted seal responsive to the perceptual distance.

13. The computer-readable storage medium of claim 12 , the computer program instructions for determining the perceptual distance between the selected image and the image of the trusted seal further comprise instructions for:

calculating a Hamming distance between the perceptual hash value of the selected image and the perceptual hash value of the image of the trusted seal.

14. The computer-readable storage medium of claim 9 , wherein the computer program instructions for verifying that the website is authorized to use the trusted seal further comprise instructions for:

providing an identifier of the website to a verification server, the verification server using the identifier to determine whether the website is authorized to use the trusted seal.

15. A system for detecting misuse of a trusted seal by a website having a plurality of images on a plurality of web pages comprising:

a non-transitory computer-readable storage medium storing executable computer program modules comprising:

an image hashing module for:

detecting that a larger image of the website contains a plurality of smaller images;

extracting the plurality of smaller images from the larger image;

determining whether spatial dimensions of the plurality of extracted smaller images are similar to spatial dimensions of images of trusted seals issued by known trusted parties to websites certified as using appropriate security procedures;

selecting at least one extracted image of the website for comparison responsive to spatial dimensions of the selected image being similar to spatial dimensions of an image of a trusted seal; and

comparing the selected image of the website to the image of the trusted seal to determine a perceptual distance between the selected image and the image of the trusted seal; and

a website verification module for, responsive to the comparison indicating that the selected image of the website matches the image of the trusted seal based on the determined perceptual distance, verifying that the website is authorized to use the trusted seal; and

a reporting module for, responsive to the verification indicating that the website is not authorized to use the trusted seal, reporting that the website is misusing the trusted seal; and

a processor for executing the computer program modules.

16. The system of claim 15 , further comprising a monitoring module for:

determining a reputation associated with the website, the reputation indicating trustworthiness of the website;

wherein the determining, selecting, comparing, verifying, and reporting steps are performed responsive to the reputation indicating that the website is untrustworthy.

17. The system of claim 15 , further comprising an image matching module for:

generating a perceptual hash value of the selected image of the website;

comparing the perceptual hash value of the selected image with a perceptual hash value generated from the image of the trusted seal to determine the perceptual distance between the selected image and the image of the trusted seal; and

determining that the selected image of the website matches the image of the trusted seal responsive to the perceptual distance.

18. The system of claim 15 , wherein the image hashing module is further for:

identifying a subset of pages of a plurality of web pages of the website that collect personally-identifiable information; and

detecting a plurality of images contained in the identified subset of pages that collect personally-identifiable information;

wherein the determining determines whether spatial dimensions of only the plurality of images contained in the identified subset of pages are similar to spatial dimensions of images of trusted seals.