DUAL LEVEL ENCRYPTED CACHE FOR SECURE DOCUMENT PRINT ON DEMAND

摘要

An on-line distributed printing network comprises a portal computer, a print manager computer 301 and at least one print service provider computer 302. The portal computer 300 and print merchant computer 301 are connected by a relatively high bit rate capacity communications link 302. The print merchant computer and print service provider computer 303 are connected by a conventional low bit rate capacity communications link 304, e.g. a 25 kilobits per second modem. The print manager computer and print service provider computer have respective first and second level cache data storage devices for storage of encrypted content data transferred from the portal to the print manager computer to the print service provider computer. Local storage of encrypted content data at the first and second level cache devices reduces the need for transmission of high volumes of content data over the communications links. Encryption of the content data is maintained throughout the communications up until a final printer device 309 which has decryption capability, thereby ensuring security of content data from portal to printer device.