Digital camera, and system for detecting falsification of an image
View Patent ↗In step S 101 , an electrical signal output from an CCD is converted into a digital signal. In step S 103 , digital data output from an analog-to-digital converter are recorded in RAM. In step S 104 , the data recorded on RAM are subjected to various image correction. In steps S 105 through S 110 , the data corrected in step S 104 are compressed in accordance with a JPEG compression scheme. In step S 106 , there is determined a location in which characteristic data are to be embedded. In step S 107 , characteristic data are produced from image data. In step S 108 , encrypted data are formed by encrypting characteristic data. In step S 109 , encrypted characteristic data are embedded into image data.
1. A digital camera, comprising:
an image pickup portion which converts light from an object to be photographed, into image data;
a producing device which produces characteristic data from the image data;
a secret key-recording portion which records a secret key to be used for encrypting data so that encrypted data can be decrypted by a public key;
an encrypting device which encrypts the characteristic data with the secret key;
an embedding device which embeds encrypted characteristic data into the image data;
a recording medium which records the image data having the characteristic data embedded therein; and
a transmitting device which transmits the secret key from an external recording medium.
2. A digital camera, comprising:
an image pickup portion which converts light from an object to be photographed, into image data;
a producing device which produces characteristic data from the image data;
a secret key-recording portion which records a secret key to be used for encrypting data so that encrypted data can be decrypted by a public key;
an encrypting device which encrypts the characteristic data with the secret key;
an embedding device which embeds encrypted characteristic data into the image data; and
a recording medium which records the image data having the characteristic data embedded therein,
wherein the secret key is recorded in the secret key-recording portion in a form of a hidden attribute.
3. A method of adding to a digital camera a function of converting light from an object to be photographed, into image data, the method comprising the steps of:
selecting, from among a plurality of data volumes, the volume of data pertaining to a secret key for encrypting data so that encrypted data can be decrypted by a public key;
recording the secret key into a secret key-recording portion of the digital camera from an external recording medium; and
loading an encryption program into the digital camera through use of the secret key.
4. The method of claim 3 , wherein the secret key is recorded in a form of a hidden attribute.
5. The method of claim 3 , wherein the secret key is selected in order to achieve a desired level of encryption sophistication.
6. An image falsification detection system using a digital camera which comprises an image pickup portion which converts light from an object to be photographed, into image data, a first producing device which produces first characteristic data from the image data, a secret key-recording portion which records a secret key to be used for encrypting data so that encrypted data can be decrypted by a public key, an encrypting device which encrypts the first characteristic data with the secret key, an embedding device which embeds encrypted first characteristic data into the image data, and a recording medium which records the image data having the first characteristic data embedded therein, the image falsification detection system comprising:
an inputting device which inputs the image data;
a removing device which removes the encrypted first characteristic data from the image data;
a decrypting device which decrypts the encrypted first characteristic data;
a second producing device which produces second characteristic data from the image data from which the encrypted first characteristic data have been removed; and
a comparing device which compares the decrypted first characteristic data with the second characteristic data.
7. The image falsification detection system of claim 6 , further comprising a recording device which records a plurality of public keys corresponding to a plurality of secret keys.
8. The image falsification detection system of claim 6 , further comprising a transmitting device which transmits the secret key from an external recording medium.
9. The image falsification detection system of claim 6 , wherein the secret key is recorded in the secret key-recording portion in a form of a hidden attribute.