Patent ID: 7508941

Claim:
A method of conducting surveillance comprising: placing a video data acquisition system (VDAS) in a public place to conduct surveillance of the public place; operating the VDAS, the VDAS producing a video signal depicting the public place, the video signal including a series of frames that correspond to different moments in time; encrypting the video signal using a first key, the first key being randomly generated such that a new randomly generated first key is used at different points in time; encrypting the first key using a second key; including at least the encrypted first key and encrypted video signal in an output signal; operating an image analyzer, the image analyzer: receiving the video signal from the VDAS; identifying a person depicted in a frame of the video signal by analyzing each frame of the video signal to look for patterns corresponding to specific persons; and for every identified person, embedding a code corresponding to that identified person in the output signal, the code being associated with the particular frame in which the pattern corresponding to the identified person was found; storing the output signal in a data storage medium; searching the data storage medium for a code corresponding to a specific person; and upon finding the code corresponding to the specific person in the data storage medium: decrypting, with the second key, the first key used to encrypt a portion of the video signal containing the frames associated with the code corresponding to the specific person; decrypting, with the decrypted first key, the portion of the video signal containing the frames associated with the code corresponding to the specific person; and displaying the portion of the video signal containing the frames associated with the code corresponding to the specific person.