The present invention relates to surveillance devices. More particularly, the present invention relates to a method and apparatus for bypass and override of privacy mode disabling functionality in surveillance devices.
Miniaturization is allowing devices suitable for optics and sound to exist within many objects that previously did not house such devices. Examples include cameras, microphones, and speakerphones that are now embedded within cellular telephones, PDAs, and watches. This development has created privacy issues with respect to unauthorized local recording or relaying sounds and/or images to other devices. Additionally, the embedding of these devices has affected products such as cellular telephones in that these once simple communication tools have become potential spying mechanisms that may violate the personal rights, dignity and freedoms of human beings.
To regulate such activity, restrictions regarding the use of such devices in certain areas are posted or searches for such devices are conducted. Unfortunately, the continuously diminishing size and integration of image and sound detection devices with other non-threatening devices, has made it very difficult to restrict their entry into given areas.
Alternatively, systems are used to broadcast radio frequency beacons that tell devices such as for example, camera telephones, to disable its camera function. However, in such systems, it is possible to block such signals to, for example, a telephone's antenna. Additionally, there are also camera telephone implementations in which the camera is not in an RF-communicating device (e.g. infrared data association (IrDA)). As a result, the device may not have any wireless communication capability. Additionally, since radio frequencies are usually not restricted to specific areas, they may propagate to other areas and affect devices that are not in restricted areas.
It is questionable whether a cooperative system is possible. Even if mandated by governments, the production of devices that do not contain the cooperative function can still occur, and there are ways to defeat such safe guards even if they are included in the equipment's production.
Accordingly, it is desirable to have a mechanism and method to regulate the use of image, sound, and other sensing devices/functions according to location, situations, and/or other authorization criteria without the need for cooperative functionality. If such sensing devices are embedded in a cellular telephone, it is desirable to regulate such cellular telephones using hardware technology that is in line with their mandated features and software.
As part of protecting privacy, camera sensed images can be altered or discarded. An alternate means to protect privacy concerns is to avoid capturing an image altogether.
Notwithstanding privacy concerns, it may be undesirable for an instructing device to remove or distort an unwilling subject from a sensed image. For example, the purpose of surveillance cameras is to catch unwilling subjects in the act of engaging in unlawful behavior. Thus, in some cases, the functionality of removing unwilling subjects from a sensed image will need to be disabled or handled in a special way. The same need may arise regarding other types of sensors such as, for example, sound sensing devices.
Approaches to dealing with the discarding of sensed data or more generally the disabling of privacy features in sensing devices have not been addressed. Digital Rights Management (DRM) techniques have been used to protect image and sound data, but these techniques have not been applied to privacy protected images and sounds. Accordingly, it is desirable to have a device and method for disabling functionality in a sensing device that removes unwilling subjects from sensed images while protecting the privacy of the sensed subjects.
A method and apparatus is provided for disabling privacy features of a surveillance device for authorized purposes. Digital information is captured and recorded by a surveillance device, which is processed according to a normal privacy mode and a bypass mode. The privacy mode processing includes features that disable sensing functions of the surveillance device. In parallel to this processing is a bypass mode processing which includes encryption and authorization of trusted entities that may access the captured information. A temporary storage device holds an amount of captured information. A processor analyzes the stored information to determine a presence of agitated activity detected that may indicate suspicious activity. A filter controls the flow of captured information to an encrypting device such that captured information related to suspicious activity is encrypted for subsequent access by an authorized entity. The filter may also be used to filter out detected information that is determined to be of a private nature by the processor.
The encrypting device encrypts the recorded information to prevent access to unauthorized persons and a storage device stores the encrypted information in an encrypted vault for future access by an authorized person. A decrypting device located in a secured location decrypts the encrypted information and a monitor located in a secured location is used for authorized viewing of the decrypted information.
In another embodiment, a surveillance device may be disabled. A sensing function senses a stimulus of the surrounding environment to produce captured information, which is recorded. An authorized fixed location is established for the surveillance device. A detector determines whether the surveillance device has been moved from the authorized fixed location installation. As a privacy feature, the sensing function of the device may be disabled or the captured information may be altered if movement of the surveillance device from its authorized fixed location has been detected.
A more detailed understanding of the invention may be had from the following description, given by way of example and to be understood in conjunction with the accompanying drawings wherein:
The captured information may be retained within the surveillance equipment itself, or offloaded to a remote location where the surveillance device is installed with communication capability. As shown in
If surveillance by devices 102, 112 is authorized, then the next decision is as to whether the capture of surveillance information is to be fully unrestricted (step 203). If so, then an override mode is selected (step 205), where the surveillance device 102, 112 is able to override any privacy functionality. For example, a disabled state of image capturing is overridden. Also, the location of such a surveillance device will be preceded by an authorization procedure to ensure that only images and sounds at authorized locations are captured. The authorization procedure is described in further detail in a later section below.
If there is not to be fully unrestricted capture of surveillance information, then a bypass mode is selected in step 204, in which surveillance device 102, 112 allows for a bypass of the privacy functionality restricting capture of images and sounds. During bypass mode, the captured information is encrypted and an authorization process is followed to access any unencrypted information.
Surveillance data, such as an image 110 and a sound 111, is received by the digital recorder 303, which is controlled by the processor 304. In a preferred embodiment, the processor 304 controls whether the recorded data is sent along one of two parallel signal paths 320, 330 which are established to maintain privacy while allowing the security function of the surveillance camera 102 to proceed. Signal 320 is preferably processed by a filter 325, which is used to filter-in captured information believed to be suspicious in nature and/or filter out captured information determined to be of a private nature. Alternatively, the captured information is unfiltered, and protection of the captured information is totally a function of encryption. Secure temporary storage device 306, in conjunction with filter 325 and processor 304, permits processing and analysis of the captured information for determining its nature and then whether it should be filtered in or filtered out. Preferably, once the captured image or sound information is filtered, then encrypting device 305 performs encryption on the filtered information, according to a preferred method which will later be described in further detail. This sequence of encryption and filtering is according to an implementation where the temporary storage is relatively for a short duration. Alternatively, should the implementation require longer periods of temporary storage for adequate filtering processing, then the information is encrypted by encryption device 305 prior to being stored in device 306 in order to ensure protection of the captured information. Storage device 326 receives the encrypted information and retains the stored information as an encrypted vault until ready to be accessed by an authorized entity 340. The authorized entity 340, such as a security officer, a law enforcement official, or the like, performs monitoring of the surveillance image data 318 and sound data 328 at monitor 308. A decrypting device 307 contains a private encryption key or keys so that the protected data can be accessed by the authorized person 340. A timed temporary memory device 338, preferably a first in first out (FIFO) memory type, stores the decrypted information temporarily so that the information can be replayed if desired by the authorized entity 340. Since the decrypted information is at risk of interception, the information is stored in the memory device only for a short duration, and is then discarded.
Where multiple monitors 308 are installed, each monitor 108 shall be accompanied by its own decrypting device 307, each with its own private key. A corresponding certificate containing a public key and information identifying the monitor is used to prove the monitor's authorized identity to the surveillance device 102, 112. The public/private keys are also used to protect a symmetric session key that will be used for the image data transmission. Preferably, the session key is periodically updated so that the data protected by a particular key will be limited.
In a parallel process, a symmetric encryption key is formed in step 403. The symmetric key is encrypted in step 406 using a public key of each monitor 308. The symmetric key is also encrypted using the public key of a first trusted access authority (step 407), which is in turn further encrypted using a public key of a second trusted access authority (step 408). (Note that there can be one or more than two trusted access authorities, in which case the encryption with public keys would accommodate the number of trusted access authorities in a tandem manner, accordingly.) The filtered information is encrypted by the symmetric key in step 409. In step 410, the encrypted keys are logically or physically associated with the encrypted information. The resulting encrypted information is now protected and can be delivered to the encryption storage device (step 411) and any connected monitors.
Alternatively, more than one symmetric key can be formed in step 403, such that a different symmetric key is used in steps 406 and 410 for the information that is sent to a monitor than that used in steps 407-410 for the information sent to encrypted storage. Also, a high rate of change is preferred for the symmetric key, but this is weighed against the increased processing load as a result.
At step 412, the symmetric key is decrypted using the monitor's private key and the information is decrypted using the decrypted symmetric key. Since each monitor has its own private key, different information can be sent to different monitors. The image or sound information can now be viewed or heard at a display terminal (step 415). Additionally, the decrypted information is temporarily stored at the monitor for possible replaying by the authorized entity (step 413), and then discarded (step 414).
While the preferred method of encryption is described herein, the present invention can also work with other methods that maintain the confidentiality of the information as it is transported to a monitor. As shown in
In the unfiltered bypass mode 504, all captured images and sounds are encrypted so that only a trusted authority can allow for the images to be accessed upon decryption. The captured images and sounds are protected by DRM or conditional access techniques, and thus are allowed to be viewed at secure monitoring stations. The decrypted information at the monitoring stations cannot be recorded in a decrypted format, but may be replayed from protected temporary storage that is discarded after a predetermined short life span. Encrypted storage of the information under the control of a DRM system may also be allowed at the monitoring stations.
In the filter-in bypass mode 505, a predetermined amount of captured information, for example 10 seconds worth of images to several days worth of images, is kept in secure non-encrypted or encrypted storage, depending on the expected duration of storage, so that intelligent image/sound processing software can analyze a stream of images and select a segment of the stream for encryption and/or for monitoring. For longer duration storage, the information is encrypted prior to storage. The processor 304 is preferably configured to receive a trigger signal initiated by detected images of sudden movement by a subject within the sensing range of the surveillance device (e.g., a quick change in the pattern of pedestrian and vehicular traffic) or by sounds with a sharp increase in volume (e.g., screams or shouts). Such indications can be analyzed to determine the type of activity captured by the surveillance device. The captured information can be classified as a normal or an agitated category, the latter indicating suspicious activity. Additionally, the captured information may be marked by a time stamp and/or a location stamp, as well as the activity type, which would be useful for searching, indexing and archiving purposes.
In the filter-out bypass mode 506, a predetermined amount of captured information is saved for analysis by intelligent image/sound processing software so that certain acts that may be officially classified as private acts and then can be filtered out or obfuscated prior to the stream of images/sounds being encrypted and/or sent to a monitoring station. A designated official or lawful entity is entrusted with specifying which activities are considered private and should be filtered out. The required algorithms or their implementation in code or pseudo code to perform the filtering can be provided by or promulgated by the official or lawful entity. Since filtering out content restricts the capture of information, this approach overlaps with the normal privacy mode 501.
To maintain the confidentiality of the surveillance request, it is encrypted in step 703 using the public key of the authorization entity (the root public key for a chain of trust of public key certificates is securely embedded in the device with integrity protections). The authorization entity or authorization body may include a court of law, state or municipal police, federal law enforcement officials, or any similar government authority or organization. In step 704, a request for surveillance is submitted to the authorization entity, using the web site of the authorization entity, where a TLS connection can provide the encryption for confidentiality, or using a web service for the direct messaging between the surveillance device and the authorization entity. If approved, in step 705 the authorization entity forms the approval certificate consisting of at least: the allowed location and the allowed time period. It may also include: the allowed reason for surveillance, and the allowed tolerance for the measured location coordinates. In step 706, the authorization body signs the approval certificate with its private key and encrypts it with the public key of the surveillance device. The message is digitally signed by a person or an organization who is granted the lawful authorization to allow the overriding of the sensor disabling privacy features at a recording device. The signed message may include an expiration date, whereby the authorized person or organization must reapply for authorization to engage the surveillance device. The authorization is stated in a digital certificate that accompanies the signature. A root certificate issued by a governmental or quasi-governmental body is preferably embedded in memory 603 or downloaded to memory 603 of each surveillance device 102, 112. This mechanism in the recording device must be tamper proof. By packaging the approval certificate with the encrypted information, it can be shown that it was obtained lawfully and can be submitted to a court of law as the certificate is permanently linked to the information. This packaging can be achieved by encrypting the captured information together with the certificate identification. An alternative method is to apply the certificate as a watermark to the captured information, using known digital watermarking techniques. To maintain the integrity of this association, the metadata and the sensed data should be digitally signed using a private key of the surveillance device.
The approval certificate is next placed in the surveillance device preferably through a web service reply message (step 707). The message will contain the device's identity, the allowed location, and a unique (one time) sequentially incrementing number. The one time number is saved by the recording device so that it can detect if an attempt is being made to re-enter a signed message.
In step 708, the surveillance device checks the signature of the certificate using a trusted root public key embedded in its secure processor (along with a possible certificate chain sent with the approval). In step 709, the surveillance device determines its location using an embedded GPS receiver, a separate trusted GPS receiver that can be physically attached to the device, or any equivalent mechanism to determine its truthful location. In step 710, the secure processor in the surveillance device determines if its measured location is within the allowed tolerance specified for the allowed location. If it is, the surveillance device disables the functionality that restricts the capturing of images or sounds. The surveillance device is now in override mode.
In step 711, the surveillance device continuously or periodically monitors its position. This can be done with an embedded GPS receiver or a self contained motion detector that can filter out normal camera panning motion. In step 712, the override mode is disabled if the surveillance device is moved and the functionality that causes the restricted capturing of images or sounds is enabled. Alternatively, the functionality that allows for images to be captured can be disabled. In an additional embodiment, the override mode is disabled if the authorized time period for surveillance according to the approval certificate has expired. This can be implemented by using an internal secure real time clock, or a tick counting mechanism as can be supplied by Trusted Computing Group's Trusted Platform Module.
Finally, in step 713, the override mode for the surveillance device can be re-enabled by placing the device back in the allowed location and using the unexpired allowance certificate or by requesting a different allowance certificate for a different location.
If the surveillance device must be moved to another location, the above described procedure must be followed again. The same technique can be used with other sensing devices, such as those described below, with slight modifications.
An example of an implementation of the above authorization procedure for the override mode is to provide a technical control over wiretaps or similar surveillance by law enforcement. For instance, a police officer who has been authorized to install a surveillance device would install a court authorized approval certificate directly in the device (e.g., a camera or audio recorder) in order to perform the electronic surveillance.
Another example of an implementation for a surveillance device in a privacy mode versus an override mode is as follows. In the normal privacy mode for a surveillance device, its sensing function has been disabled and it is stored in a law enforcement agency's stock room. Following a request for override mode, a court order is issued, and an authorized approval certificate is issued. This certificate which can restrict the sensing device to operate in a certain location, or during a certain period of time, or both, is installed in the sensing device which is designated in the certificate. The sensing device can then enter the override mode which in this case means that it goes from a disabled state of sensing to an enabled state of sensing. This example can be extended from a law enforcement agency to any party that would like to set up a surveillance device, although typically in this case, the device when entering override mode will go from a state of somewhat restricted sensing to a state of fewer or no restrictions (other than being limited by location and/or time).
The following sensing and reporting functions for surveillance device 102, 112 are examples of what may be enabled or disabled if the device 102, 112 is removed from its authorized fixed location: recording functions, notification or alerting systems either local or remote, data distortion, downsampling ability, transfer of the captured information, auditing, watermarking or fingerprinting.
With respect to data distortion, camera image blurring may be used to address the unwanted sensing of images with cameras. For instance, an interference mechanism may operate against the auto-focusing mechanism in image sensing devices (e.g., cameras) so that a sensed image is blurred. Copending application entitled Method and Implementation for Using Infrared Signals and Sonar to Interfere with Camera Autofocus Mechanism, describes continuous or intermittent emitters to confuse the auto focusing mechanisms in cameras. These emitters can cause sensed images to be blurred and unusable. Multiple infrared emissions of varying intensities will also cause under-exposure or over-exposure lighting in sensed images. Such emitters can be manually controlled to intentionally alter captured surveillance information as a privacy feature, by manual entry of codes, restricting operation to occur only by devices having a security decoding means, and/or logging onto a network or access point with appropriate authentication and access codes to obtain access to enablement information. This manual control may be overridden if the camera if moved from its authorized location.
Wireless communication between the surveillance device 102, 112 and a wireless transceiver creates a mechanism for automatically reporting events that require attention by setting up a call to a call processing center or a specified phone number. For example, a mobile phone can automatically receive information sent by a transmitter 604 within surveillance device 102, 112 when a security breach or unlawful activity is detected. Location of the surveillance device 102, 112 is also transmitted to assist with emergency response. Communication between the surveillance device 102, 112 a mobile phone can occur over infrared (IR), Bluetooth, or any other wireless or wired interface. The reporting of a sensor may be periodic or only when a sensor detects a situation within a pre-determined operating range. If surveillance device 102, 112 is moved from its authorized fixed location, such communication functionality is disabled, such as by disabling transmitter 404.
As shown in
Although the features and elements of this embodiment are described in particular combinations, each feature or element can be used alone (without the other features and elements of the preferred embodiments) or in various combinations with or without other features and elements of the present invention.
This application claims the benefit of U.S. provisional application No. 60/631,328, filed on Nov. 29, 2004 and U.S. provisional application No. 60/633,527 filed on Dec. 6, 2004, which are incorporated by reference as if fully set forth.
Number | Date | Country | |
---|---|---|---|
60631328 | Nov 2004 | US | |
60633527 | Dec 2004 | US |