Methods and apparatus for secure document printing

• US 20040008842A1
• Filed: 07/10/2002
• Published: 01/15/2004
• Est. Priority Date: 07/10/2002
• Status: Active Grant

• Current Assignee: Fiery LLC
• Original Assignee: Electronics For Imaging Incorporated
• Inventors: Faramani, Mehran, Fulton, Truxton, Partelow, Mike
• Granted Patent: US 7,296,157 B2
• Time in Patent Office: Days
• US Class Current: 380/51
• CPC Class Codes: G06F 3/1205 resulting in increased flexibility in print job configuration, e.g. job settings, print requirements, job tickets
• CPC Class Codes: G06F 3/1222 Increasing security of the print job
• CPC Class Codes: G06F 3/1238 Secure printing, e.g. user identification, user rights for device usage, unallowed content, blanking portions or fields of a page, releasing held jobs
• CPC Class Codes: G06F 3/1285 Remote printer device, e.g. being remote from client or server
• CPC Class Codes: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols

Abstract

Methods and apparatus are provided for securely printing a print job on a networked printer. An application program running on a networked computer instructs the printer to generate and exchange cryptographic keys. The application program then encrypts the print job using the keys, and then communicates the encrypted print job to the printer. The printer decrypts the received print job and prints the document.

Claims

7-1. The method of claim 1, wherein the first set of computer program instructions comprises a PostScript procedure.

8-2. The method of claim 1, wherein the second set of computer program instructions also is adapted to cause the printer to modify a file read operation.

11. A method for securely communicating print data from a client computer to a networked printer, the method comprising:

providing a first set of computer program instructions from the client computer to the printer, the first set of computer program instructions causing the printer to generate a first cryptographic key;

generating a second cryptographic key at the client computer;

encrypting the print data using the second cryptographic key;

providing a second set of computer program instructions from the client computer to the printer, the second set of computer program instructions causing the printer to decrypt the encrypted print data.

12. The method of claim 11, wherein the first set of computer program instructions causes the printer to generate public and private keys of a key encryption algorithm.

13. The method of claim 12, wherein the second cryptographic key is a shared secret key generated according to the Diffie-Hellman key agreement protocol.

14. The method of claim 11, wherein the print data are encrypted using a cipher.

15. The method of claim 11, wherein the first set of computer program instructions comprises a PostScript procedure.

16. The method of claim 11, wherein the second set of computer program instructions comprises a PostScript procedure.

17. A method for securely printing print data from a client computer to a networked printer, the method comprising:

generating a public and private cryptographic key pair at the client computer;

providing a key exchange program from the client computer to the printer, the key exchange program generating a public and private cryptographic key pair at the printer and exchanging the public key of the printer with the public key of the client computer;

providing a decryption program from the client computer to the printer, the decryption program modifying a file read operation at the printer;

encrypting the print data at the client computer and communicating the encrypted print data to the printer;

implementing the modified file read operation at the printer to decrypt the encrypted print data.

18. The method of claim 17, further comprising rendering the decrypted print data at the printer.

19. The method of claim 17, wherein the key exchange program comprises a PostScript procedure.

20. The method of claim 17, wherein the decryption program comprises a PostScript procedure.