1. Field of the Invention
The present invention generally relates to a system restricting printing operations or the like.
2. Description of the Related Art
Recently, in systems restricting printing operations, a reduction of a total cost of ownership (TCO), including not only an initial cost for introducing printers and systems but also a cost for supplies such as printing sheets and coloring agents as represented by toners, has received significant attention for reducing office costs or for promoting global environmental conservation.
When a printer is installed in an office, anyone can perform a printing operation using the printer if they can access a network, which has been a problematic issue. Since anyone can perform a printing operation without any restrictions with regard to the number of printed sheets and users have no imposed limits, printing operations are often performed in which the number of printing sheets exceeds the necessary quantity. This undesirably results in an increase in office costs.
When considering this issue from a viewpoint of administrators of systems or devices, it is desired to set available functions and limitations on the available number of sheets for each user in an integrated fashion and to manage quantities of resources. For example, the number of sheets that each user can consume may be limited to an appropriate level.
To cope with such issues, many printing systems implementing restrictions of printing operations or management of the number of printing sheets are realized. For example, a printing system realizes restrictions of printing operations using address information, such as IP addresses of transmission control protocol/internet protocol (TCP/IP), which is a first method. Another system realizes management of the number of printing sheets by acquiring a print operation log, which is a second method. However, since the first method is a simplistic method for imposing restrictions on specific IP addresses, strict management, such as imposing restrictions on the number of sheets that specific users can use, cannot be performed. In addition, according to the second method, a log can be preserved by printing the log. However, administrators have to monitor the log all of the time to investigate whether unauthorized printing operations have been performed, which requires a significant personnel cost. For this reason, the second method deviates from the spirit of the TCO reduction.
To address the above-described issues, for example, an invention disclosed in Japanese Patent Laid-Open No. 2004-185629 has been suggested. The invention disclosed in Japanese Patent Laid-Open No. 2004-185629 is designed to restrict output operations. More specifically, a management server on a network creates a “print right token” for each user, and delivers the print right token to a host computer used by each user prior to the printing operation. An image forming apparatus (e.g., a printer driver) in the host computer sends the acquired print right token together with a print job. An image processing apparatus (e.g., a printer) restricts the number of output sheets and functions according to information written in the print right token that the image processing apparatus has received together with the print job.
Furthermore, to prevent the print right token from being tampered with and function restrictions for each user from being intentionally cancelled in the above-described systems, a printing system that sends an entire print job including a print right token in a format enabling tamper detection is under development. Even if a print job having been tampered with by a malicious user is sent, this printing system can detect the tampering and discard the printing request.
However, printing systems capable of receiving a print job in a tamper detectable format and processing the print job are limited to those having a tamper detection processing function. Even printers of a related series sharing a specification of the same printer description language (PDL) may not be utilized by users as printers included in the printing system. In addition, even if a printer included in a printing system is capable of handling a print job in a tamper detectable format, there may be a case where the printing system is desired to work in cooperation with other printing solutions, such as, for example, a system that archives and stores print jobs in a storage device. In such a case, the printer has to work after switching a working mode into a mode enabling processing of jobs in a normal format but not in a tamper detectable format, which may also be problematic.