Image forming apparatus, image forming method and, computer readable medium and computer signal

• US 20080044021A1
• Filed: 03/22/2007
• Published: 02/21/2008
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Ono, Katsuhiko, Nishigai, Hidefumi, Tsuji, Masato
• Granted Patent: US 8,331,562 B2
• Time in Patent Office: Days
• US Class Current: 380/243
• CPC Class Codes: H04N 1/448 Rendering the image unintelligible, e.g. scrambling

Abstract

An image forming apparatus comprises: an output part that outputs variable information varying in a time-dependent manner in the image forming apparatus; a first encrypt part that encrypts the variable information outputted from the output part using a first encrypt key read out from a memory; a second encrypt key create part that creates a second encrypt key according to the variable information outputted from the output part; a second encrypt part that encrypts inherent information for specifying the image forming apparatus using the second encrypt key created by the second encrypt key create part; a generate part that generates code data according to the variable information encrypted in the first encrypt part and the inherent information encrypted in the second encrypt part; and an image form part that forms on a recording member a code image based on the code data generated in the generate part.

Claims

1. An image forming apparatus comprising:

an output part that outputs variable information varying in a time-dependent manner in the image forming apparatus;

a first encrypt part that encrypts the variable information outputted from the output part using a first encrypt key read out from a memory;

a second encrypt key create part that creates a second encrypt key according to the variable information outputted from the output part;

a second encrypt part that encrypts inherent information for specifying the image forming apparatus using the second encrypt key created by the second encrypt key create part;

a generate part that generates code data according to the variable information encrypted in the first encrypt part and the inherent information encrypted in the second encrypt part; and

an image form part that forms on a recording member a code image based on the code data generated in the generate part.

2. An image forming apparatus as set forth in claim 1,

wherein the output part outputs, as the variable information, at least one of time information, information about the number of times a power switch is put to work, information about the number of sheets printed, and information about random number to be outputted by a random generator provided in the image forming apparatus.

3. An image forming apparatus as set forth in claim 1, further comprising:

a read part that reads the code image formed on the recording member;

a first analyze part that analyzes the variable information from the code image read by the read part using the first encrypt key;

an encrypt key create part that creates the second encrypt key based on the variable information analyzed in the first analyze part; and

a second analyze part that analyzes the inherent information from the code image read in the read part using the second encrypt key created in the encrypt key create part.

4. An image forming apparatus comprising:

an output part that outputs variable information varying in a time-dependent manner in the image forming apparatus;

a first pattern data create part that creates pattern data from the variable information outputted from the output part;

a second pattern data create part that creates a plurality of pieces of pattern data from inherent information for specifying the image forming apparatus, and rearranges the plurality of pieces of pattern data based on the variable information outputted from the output part;

a generate part that generates code data based on the pattern data created in the first pattern data create part and the plurality of pieces of pattern data rearranged in the second pattern data create part; and

an image form part that forms on a recording member a code image based on the code data generated in the generate part.

5. An image forming apparatus as set forth in claim 4,

wherein the output part outputs time information as the variable information, and

the second pattern data create part moves the plurality of pieces of pattern data sequentially based on the time information so as to rearrange the plurality of pieces of pattern data.

6. An image forming method comprising:

encrypting variable information varying in a time-dependent manner in an image forming apparatus using a first encrypt key read out from a memory;

creating a second encrypt key from the variable information;

encrypting inherent information for specifying the image forming apparatus using the second encrypt key; and

generating a code image based on the variable information encrypted by the first encrypt key and the inherent information encrypted by the second encrypt key.

7. A computer readable medium storing a program causing a computer ton execute a process for generating an image, the process comprising:

encrypting variable information varying in a time-dependent manner in an image forming apparatus using a first encrypt key read out from a memory;

creating a second encrypt key from the variable information;

encrypting inherent information for specifying the image forming apparatus using the second encrypt key; and

generating a code image based on the variable information encrypted by the first encrypt key and the inherent information encrypted by the second encrypt key.

8. A computer signal embodied in a carrier wave for enabling a computer to perform a process for generating an image, the process comprising:

encrypting variable information varying in a time-dependent manner in an image forming apparatus using a first encrypt key read out from a memory;

creating a second encrypt key from the variable information;

encrypting inherent information for specifying the image forming apparatus using the second encrypt key; and

generating a code image based on the variable information encrypted by the first encrypt key and the inherent information encrypted by the second encrypt key.