Patent ID: 7454797

Claim:
A method comprising: evaluating multimedia to determine authenticity of the multimedia, the evaluating being based on data block(s); and responsive to determining that the multimedia is not authentic, localizing a tampered portion of the multimedia, the localizing further comprising: shuffling a challenged image to generate a shuffled image with randomized neighborhood data; converting the shuffled image and an original logo image into lower dimension vectors; the original logo image being a second image embedded into the multimedia to be signed in a signing procedure to detect tampered pixels or samples; extract the embedded logo from a lower dimension vector of the lower dimension vectors that corresponds to the challenged image comparing the extracted logo with the original logo to identify mis-matched pixel(s) or sample(s); scanning the lower dimension vectors to higher dimension vectors by reversing previously applied dimension reduction operations; reversing the shuffling operation to locate particular pixel(s) or samples of the multimedia that correspond to the mismatched pixel(s) or sample(s) in the shuffled image; and wherein the particular pixel(s) or sample(s) are tampered pixel(s) or sample(s).