GB2462163A

GB2462163A - Digital Camera with automatic image and metadata encryption.

Info

Publication number: GB2462163A
Application number: GB0910180A
Authority: GB
Inventors: Errol Finkelstein; John Meyer; Roshen Kajie; Andrew Briton; Nick Branco
Original assignee: REDZEBRA MOBILE Ltd
Current assignee: REDZEBRA MOBILE Ltd
Priority date: 2008-06-12
Filing date: 2009-06-12
Publication date: 2010-02-03
Also published as: GB0910180D0; GB0810734D0

Abstract

Methods and systems for generating and verifying image and metadata. A digital camera or a mobile telephone or personal digital assistant (PDA) which incorporates a camera comprises software for automatically encrypting the image 31a and meta-data 31b associated with a captured photograph. The metadata includes time/date and positional data generated using a global positioning system (GPS). Further, a checksum 41 is generated using the image and metadata and automatically encrypted. The encryption can involve secure keys updated periodically. Also claimed is a verifying server receiving the encrypted image, metadata and checksum, and using the checksum to verify the image and metadata were not tampered with. If verified, the decrypted image and metadata can be stored and/or displayed, for example within verified sections of a website, and optionally displayed with a human readable form of the metadata, such as a map of the location in which the image was captured.

Description

Digital Camera System and Method of Operation Thereof The present invention relates to a digital camera system, particularly, though not exclusively a digital camera system embodied in a mobile device such as a mobile telephone or Personal Digital Assistant (PDA), and method of operation thereof. The invention also relates to a verification system and method of operation thereof.

It is common for mobile electronic devices, such as mobile telephones and Personal Digital Assistants (PDAs), to include a camera enabling the capturing of digital pictures/images for onwards transmission to other devices by means a suitable data protocol, for example using Mobile Messaging Service (MMS), Bluetooth, General Packet Radio Service (GPRS), Email or 3G protocols. Some *:::1 devices also enable positional information to be associated with captured *....* images. The positional information may be generated at the time of image capture using a Global Positioning System (GPS) receiver provided as part of the :.:,:* device, or one which is provided separately and connected to the device when in use. By associating, or tagging', an image with its positional information, the * 20 user (and indeed the party to whom the image is sent) is able to see where the image was taken, typically using software or websites which interpret the S.....

* positional information to provide a text label or position displayed on a map.

Google EarthTM is a well known example of such an application. This process of generating and associating positional information with captured images is often called geocoding' or geotagging'. Geocoding is useful in that, amongst other advantages, it enables users to conveniently keep track of where their images were taken and to catalogue them appropriately.

As well as positional data, other types of such metadata commonly tagged to images include the date and time of capture, camera settings, and so on. In the case of many camera systems, this metadata is stored as part of the so-called EXIF (Exchangable Image File Format).

It will be appreciated that image data and metadata can be altered, not only at the camera device itself but also at any terminal to which the image data and metadata is transferred. For example, the image data might be modified using a standard graphics application to change a registration plate on a vehicle.

Alternatively, the metadata might be changed simply by editing the file properties to show a different date and location. Generally speaking, this is not an issue since the user is free to modify their images as they see fit. However, in certain applications, it would be useful for the intended recipient to be assured of the image's accuracy in terms of captured content and metadata. For example, in the event of a vehicle accident, images taken immediately after the accident might provide valuable evidence to the police and insurance assessor. However, such evidence is only likely to be considered valid if the police and assessor can be assured of the image and metadata's accuracy.

S * * * ***

In one sense, the invention provides a method of operating a digital camera :.:::. system to generate an image for verification at a remote system, the method comprising: capturing a digital image, and in response thereto, automatically encrypting image data representing said digital image and metadata representing attributes of said digital image.

****** * S The method may further comprise automatically generating a checksum using the image data and metadata in response to image capture, and encrypting the checksum to provide a further set of encrypted data.

The metadata may include time/date information indicative of the time/date at which image capture took place. The metadata may include positional data indicative of the geographical position of the digital camera at the time of image capture. The positional data may be generated using a GPS device arranged automatically to generate said data at the time of image capture. Said GPS device can also be used to provide accurate time/data information.

The encryption can be performed using a key or keys that is/are unique to said camera system. Encryption may be performed using different encryption keys which are respectively employed for encrypting each of the image, metadata and checksum data.

The encryption can be performed using a key or keys that is/are updated periodically, for example each time an image is captured or following a predetermined time.

The above-described method can be performed at a wireless data transmitter, for example a mobile telephone or PDA, arranged to transmit said encrypted data wirelessly to a remote verification system. S... * S * .

****** According to a second aspect, there is provided a method of receiving data indicative of captured images from a digital camera system, the method :.:::. comprising: receiving from the digital camera system (i) encrypted image data representing a digital image and (ii) encrypted metadata representing attributes of said digital image, identifying a decryption key or keys associated with the : digital camera system that transmitted the data, and decrypting said image data ***.

* and its associated metadata using the identified decryption key or keys.

The method may further comprise receiving an encrypted checksum, decrypting said checksum using the identified key or keys and identifying the validity of the decrypted image and metadata on the basis of the decrypted checksum. The method may further comprise extracting positional data from the decrypted metadata and referencing said positional data with a library to generate a human readable indication of the location where the image was taken, for example a

map or street/city/country level description.

According to a third aspect, the digital camera system is arranged to operate according to the above described method or preferred steps.

According to a fourth aspect, there is provided a digital camera system comprising: capture means for generating a digital image; a control system arranged, in response to an image being captured, automatically to encrypt image data representing said digital image and metadata representing attributes of said digital image.

The control system may further be arranged to generate a checksum using the image data and metadata, to encrypt the checksum to provide a further set of encrypted data, and means arranged to transmit said encrypted data to a remote verification system.

*:::5 A digital camera system may be embodied in a wireless data transmitter such as *:::* a mobile telephone or PDA and arranged to transmit the encrypted data using a wireless transmission protocol such as MMS, GPRS or 30. The system may :.:::* further comprise a integral GPS receiver arranged to generate location metadata automatically upon capture of an image.

According to a fifth aspect, there is provided a method of operating a mobile data S.....

* S transmitter, for example a mobile telephone or PDA, incorporating a camera and global positioning system, the method comprising: capturing a digital image, and in response thereto, automatically encrypting (i) image data representing said digital image, (ii) metadata including positional data from the global positioning system indicative of the location of image capture and (iii) a checksum based on the image data and metadata.

According to a sixth aspect, there is provided a method of receiving data indicative of captured images from a mobile data transmitter, for example a mobile telephone or PDA incorporating a camera and global positioning system, the method comprising: (a) receiving from the transmitter (i) encrypted image data representing a digital image, (ii) encrypted metadata including positional data indicative of the location of image capture and (iii) a checksum, (b) identifying a decryption key or keys associated with the digital camera system that transmitted the data, (c) decrypting said checksum to verify the validity of the image and metadata and, if verified, providing the decrypted image and a human readable indication of the location of image capture based on the decrypted metadata.

There is also provided a computer program or suite of computer programs stored on a computer readable medium and being arranged, when executed on a processing system, to perform the steps of any one of abovementioned steps.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: *** a * . Figure 1 is a block diagram showing a communications system which includes a :.:.. digital camera device; Figure 2 is a block diagram indicating operating functions of dedicated software provided at the digital camera device; : Figure 3 is a flow diagram indicating processing steps performed by the * .*.** * dedicated software; Figure 4 is a block diagram indicating operating functions of verifying software provided at a remote server; Figure 5 is a flow diagram indicating processing steps performed by the verifying software; and Figure 6 shows a verified image as displayed at a remote server, including a verified set of metadata associated with the image and a map indicative of where said image was taken.

Referring to Figure 1, a communications system incorporating an image capture device is shown. The image capture device is, in this case, a 3G mobile telephone 1 with built-in digital camera. As well as having conventional GSM/3G call functionality, the telephone 1 can also transmit and receive data to other systems 5, 7 via network 3 using standard protocols such as MMS, Bluetooth, GPRS and Email. The telephone I also comprises a built-in GPS receiver 8 for generating positional data indicative of the longitude and latitude at which image are captured. Such telephones are known and examples include the Nokia N95 smart phone running the Symbian S60 platform. Alternatively, the telephone I could be a PDA or conventional mobile telephone arranged to receive positional W data from a separate GPS receiver over a wired or wireless link. In accordance with conventional operation, when an image is captured using the platform's standard camera facility, metadata including image name, date/time and positional data from the GPS receiver 8 is associated or tagged to the image in the form of art EXIF file. I.. * * ** *

First and second servers 5, 7 are shown connected to the network 3. The first * *_* server 5 is a server from which a dedicated camera application 6 can be downloaded to the telephone 1 via the network 3. In use, the user of the telephone 1 connects to the first server, accesses a registration portal into which *, 20 user details are entered, and thereafter downloads the camera application 6.

This download can be by the use of, for example, email, MMS, Bluetooth, GPRS, **. .** * 3G and so on. Upon completion of the download, the user installs the application 6 to run on their telephone. In this example, the application 6 is arranged to operate in conjunction with the camera's standard hardware and smart phone platform to process, automatically, captured images and metadata to ensure certain third-party requirements can be met in terms of security and verification.

The second server 7 is a third-party image repository to which users upload captured images to the server over the network 3. This enables images to be catalogued in a user's account for personal viewing and/or forwarding to other third parties. Cataloguing may be performed using the metadata, e.g. so that images are arranged in folders according to date, location or a combination of both. In terms of location, the positional metadata is converted at the second server 7 to generate a map representation of where the image was taken. When a user selects an image to view, both the image and map representation are displayed.

The use of first and second servers 5, 7 is not essential and a single server can be employed for both software provision and storing uploaded image content.

Conventionally, users (and others) can modify images and their associated metadata. In certain situations, it would be desirable to prevent this in order that third parties can be assured of a particular image's authenticity in terms of its content and attributes. If an image is to be used as evidence, for example to show that a traffic accident occurred at a particular time and place, some level of assurance would be highly beneficial. To facilitate this, the camera application 6 is arranged automatically to process the image data and associated metadata in : .. such a way that verification can be made at the second server 7. In this way, the second sever 7 provides a trusted facility by means of which other third parties, such as insurance assessors, the police etc., can be assured that the uploaded .20 data has not been tampered with, either by the user or an intercepting party, between time of capture and receipt at the second server 7. The operation of the camera application 6 and second server 7 will now be described.

Upon launch of the camera application 6, the telephone 1 provides a user interface much like that of conventional image capture software, i.e. presenting a viewer window and options for adjusting camera sethngs. Referring to Figures 2 and 3, in a first step 3.1, an image is captured in response to user actuation (although this could be done automatically, e.g. using a timer.) In a second step 3.2, the application 6 generates image data representing the captured image 31a and a set of metadata 31b indicating the name of the image, the date, time and positional data in terms of longitude and latitude as generated by the GPS receiver 8. Next, in step 3.3, the image data 31a and metadata 31b are separately encrypted to provide respective encrypted files 35, 39. In a fourth step 3.4, a checksum 41 of the image data 31a and metadata 31b is generated.

In a fifth step 3.5, this checksum 41 is also encrypted to provide a further encrypted file 37. Steps 3.2 to 3.5 are performed automatically by the application 6 without user intervention. In a sixth step 3.6, the encrypted files 35, 37, 39 are transmitted to an intended recipient, in this case the second server 7, using a selected communications protocol.

The encryption and checksum algorithms employed by the application 6 can be any known encryption or checksum type algorithm, for examp'e, for the checksum, a cryptographic hash function or just a basic checksum. However, the encryption keys at least used should not be readily accessible to the user. The :. algorithm routines and keys are securely stored in the telephone's memory by the J5 application 6. The keys provided to the telephone 1 will be particular to that telephone and assigned during the registration process at the first server 5. * *. * I I ****

In the preferred embodiment, each line in the EXIF file is encrypted so that both the image and the metadata is totally encrypted. It is also possible to encrypt the *.20 EXIF file and image with different encryption keys so that, if someone were to :: crack one encryption and, say, decrypt the image, the EXIF cannot itself be decrypted without encrypting the other encryption key. This makes it much more difficult to crack both sets of data. A still further different encryption key might be employed for the third checksum encryption to provide another level of security.

Further options as regards encryption include using a unique identifier associated with the mobile telephone as part of the encryption key. Unique encryption key(s) could be downloaded on a per session' basis with a session being defined as each time an encryption operation is to take place or after a predetermined amount of time, e.g. every ten days. This means that anyone cracking one or more keys will only be able to use that key for a limited amount of time before the key expires. From the above, it will be apparent that one can use key(s) that is/are unique to the phone and/or unique to a session.

Referring to Figures 4 and 5, the operating steps performed by verification software running at the second server 7 will now be described. In a first step 5.1, the encrypted files 35, 37, 39 are received from the network 2 and separately decrypted 41. More specifically, in a second step 5.2, the originating telephone 1 is identified and the relevant decryption key or keys retrieved. In a third step 5.3, each of the encrypted metadata file 39, image file 35, and checksum file 37 is decrypted using the retrieved key or keys. In a fourth step 5.4. verification of the decrypted image and metadata files 35', 39' is performed by verifying the decrypted checksum 37'. If verified, the decrypted image and metadata flies 35', 39' are themselves verified as being authentic in terms of image content and :. metadata and thereafter stored in a verified area of the image repository (step :.J5 5.5). If the checksum does not verify, an error message is presented and/or the decrypted image content and metadata is stored in a non-verified area of the . image repository (step 5.6).

Referring to Figure 6, an example of verified output is shown. A particularly *4�=O advantageous application of the system is not only the display of the verified :: image and its metadata but also an indication of where the image was taken.

This is achieved by referencing the verified metadata to a library which identifies the location indicated by the latitude and longitude metadata to display its graphical location, e.g. on a map. Additionally or alternatively, a text description of the location can be shown, here being the suburb, postal code and country of where the image was taken. To achieve this, the metadata can be referenced automatically at the server 7 upon verification to a dedicated library stored at the server or to a third party library, for example the ViamichelinhM library (see www.viamichelin.com) which generates the map and/or textual information in response to the positional metadata, in this case the latitude and longitude. The output as shown in Figure 6 is made available to an image repository accessible to the particular user or which can be shared within a user group or made available to selected third parties, e.g. the police or an insurance company, should a verified indication of image content and image location be required.

As indicated in Figure 6, a date and time stamp is stored indicating the time of receipt at the server 7 which may also be required by third parties.

The abovementioned automatic encryption, checksum generation and, at the server end, verification, decryption and, if required, positional referencing and display are performed using software or a suite of software programs.

In summary, the above-described method and system enables captured images and associated metadata to be securely transferred to a remote location in such a way that a recipient or interested third party can determine whether or not the ::.fs image data and/or metadata was altered between the stages of capture and receipt. At the telephone end of the link, this is provided for by dedicated ::::. software which can be provided with the telephone 1 or downloaded to memory at a later time, e.g. from a web portal as in the case of the above-described embodiment. At the server end 7, functionality is provided to enable verification 2O of received images and, as in the example mentioned above, to reference * verified nietadata to a library to provide a graphical or text indication of where the image was captured. Although the embodiment describes the use of mobile telephone I as the image capture device, any device having image capture functionality and access to a data network can employ the software in a similar manner.

Claims

Claims 1. A method of operating a digital camera system to generate an image for verification at a remote system, the method comprising: capturing a digital image, and in response thereto, automatically encrypting image data representing said digital image and metadata representing attributes of said digital image.
2. A method according to claim 1, further comprising automatically generating a checksum using the image data and metadata in response to image capture, and encrypting the checksum to provide a further set of encrypted data.
3. A method according to claim I or claim 2, wherein the metadata includes :. time/date information indicative of the time/date at which image capture took ::. place. * *..

::::.
4. A method according to any preceding claim, wherein the metadata includes positional data indicative of the geographical position of the digital camera at the time of image capture. *1
5. A method according to claim 4, wherein the positional data is generated using a GPS device arranged automatically to generate said data at the time of image capture.
6. A method according to claim 5, wherein said GPS device is also used to provide accurate time/data information.
7. A method according to any preceding claim, wherein said encryption is performed using a key or keys that is/are unique to said camera system.
8. A method according to any preceding claim, wherein said encryption is performed using different encryption keys which are respectively employed for encrypting each of the image, metadata and checksum data.
9. A method according to any preceding claim, wherein said encryption is performed using a key or keys that is/are updated periodically, for example each time an image is captured or following a predetermined time.
10. A method according to any preceding claim, said method being performed at a wireless data transmitter, for example a mobile telephone or PDA, arranged to transmit said encrypted data wirelessly to a remote verification system.
11. A method of receiving data indicative of captured images from a digital camera system, the method comprising: receiving from the digital camera system :. (i) encrypted image data representing a digital image and (ii) encrypted metadata representing attributes of said digital image, identifying a decryption key or keys associated with the digital camera system that transmitted the data, and : .. decrypting said image data and its associated metadata using the identified S. decryption key or keys.

2IO
12. A method according to claim 11, further comprising receiving an encrypted checksum, decrypting said checksum using the identified key or keys and identifying the validity of the decrypted image and metadata on the basis of the decrypted checksum.
13. A method according to claim 11 or claim 12, further comprising extracting positional data from the decrypted metadata and referencing said positional data with a library to generate a human readable indication of the location where the image was taken, for example a map or street/city/country level description.
14. A digital camera system arranged to operate according to any one of claims Ito 10.
15. An image verification system arranged to operate according to any one of claims 11 to 13.
16. A digital camera system comprising: capture means for generating a digital image; a control system arranged, in response to an image being captured, automatically to encrypt image data representing said digital image and metadata representing attributes of said digital image.
17. A digital camera system according to claim 16, wherein the control system is further arranged to generate a checksum using the image data and metadata, to encrypt the checksum to provide a further set of encrypted data, and means arranged to transmit said encrypted data to a remote verification system.
18. A digital camera system according to claim 16 or claim 17 embodied in a ** wireless data transmitter such as a mobile telephone or PDA and arranged to ::. transmit the encrypted data using a wireless transmission protocol such as MMS, GPRS or 3G.

.2.Q
19. A digital camera system according to any one of claims 16 to 18, further comprising a integral GPS receiver arranged to generate location metadata automatically upon capture of an image.
20. A method of operating a mobile data transmitter, for example a mobile telephone or PDA, incorporating a camera and global positioning system, the method comprising: capturing a digital image, and in response thereto, automatically encrypting (i) image data representing said digital image, (ii) metadata including positional data from the global positioning system indicative of the location of image capture and (iii) a checksum based on the image data and metadata.
21. A method of receiving data indicative of captured images from a mobile data transmitter, for example a mobile telephone or FDA incorporating a camera and global positioning system, the method comprising: (a) receiving from the transmitter (i) encrypted image data representing a digital image, (ii) encrypted metadata including positional data indicative of the location of image capture and (iii) a checksum, (b) identifying a decryption key or keys associated with the digital camera system that transmitted the data, (c) decrypting said checksum to verify the validity of the image and metadata and, if verified, providing the decrypted image and a human readable indication of the location of image capture based on the decrypted metadata.
22. A computer program or suite of computer programs stored on a computer readable medium and being arranged, when executed on a processing system, to perform the steps of any one of claims Ito 13,20 and 21.:::**
23. A digital camera system constructed and arranged substantially as herein shown and described with reference to the drawings. * ** * . * S. * S * SS.SS..... *