# US 9,883,072 B2 · Encrypted file printing system, encrypted file printing method, and encrypted file print control program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,883,072 B2 - Document ID: US9883072B2 - Status: Granted - Kind: B2 - Application number: 15/370,133 - Filed: 2016-12-06 - Published: 2017-06-08 - Granted: 2018-01-30 - Earliest claimed: 2015-12-07 - Assignees: Konica Minolta, Inc. - Applicants: Konica Minolta, Inc. - Inventors: Katsuyuki Taima - Web page: https://patentgrep.com/patent/US9883072B2 ## CPC - H04N 1/32272: {Encryption or ciphering} - G06F 3/1213: {at an intermediate node or at the final node} - G06F 3/1222: {Increasing security of the print job} - 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} - G06F 3/1244: {Job translation or job parsing, e.g. page banding} - G06F 3/1285: {Remote printer device, e.g. being remote from client or server} - G06K 15/1823: {for evaluating the resources needed, e.g. rasterizing time, ink, paper stock} - G06K 15/1861: {taking account of a limited available memory space or rasterization time} - G06K 15/4095: {Secure printing (computer driven secure printing G06F3/1238)} - H04L 9/0861: {Generation of secret information including derivation or calculation of cryptographic keys or passwords} - H04L 9/321: {involving a third party or a trusted authority} - H04L 9/3226: {using a predetermined code, e.g. password, passphrase or PIN (network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083)} - H04L 9/3297: {involving time stamps, e.g. generation of time stamps} - H04N 1/00344: {with a management, maintenance, service or repair apparatus (monitoring H04N1/00002)} - H04N 1/444: {to a particular document or image or part thereof} - H04N 2201/0094: Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception - H04N 2201/3228: further additional information (metadata) being comprised in the identification information - H04N 2201/3281: Encryption; Ciphering - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An encrypted file printing system includes: a client terminal configured to generate a print file; an authorization management server configured to manage authorization of the print file; and an image forming apparatus configured to perform printing of the print file, the client terminal, the authorization management server, and the image forming apparatus being connected by a communication network, wherein the authorization management server includes: a key generating unit; and a decrypting unit, the client terminal includes: an encrypting unit; and a print instructing unit, the image forming apparatus includes: a decrypting unit; a rasterizing unit; a memory; and a control unit, and the control unit includes: a complexity calculating unit; a processing time calculating unit configured to calculate a first processing time in a first processing mode and a second processing time in a second processing mode; and a decryption destination determining unit. ## Claims ### Claim 1 An encrypted file printing system comprising: a client terminal generating a print file; an authorization management server managing authorization of the print file; and an image forming apparatus performing printing of the print file, the client terminal, the authorization management server, and the image forming apparatus being connected by a communication network, wherein the authorization management server includes: a key generating unit generating an encryption key for the print file and a decryption key for an encrypted file generated by encrypting the print file; and a decrypting unit decrypting the encrypted file, the client terminal includes: an encrypting unit encrypting the print file and generating the encrypted file, using the encryption key obtained from the authorization management server; and a print instructing unit adding file information as metadata to the encrypted file, transmitting the file information to the image forming apparatus, the file information indicating a structure of the print file, the image forming apparatus includes: a decrypting unit decrypting the encrypted file; a rasterizing unit rasterizing the print file; a memory to be used by the decrypting unit and the rasterizing unit; and a control unit, and the control unit includes: a complexity calculating unit receiving the encrypted file, and reading the file information added to the encrypted file and calculating a rasterization complexity in the image forming apparatus in accordance with the file information before the decrypting unit decrypts the encrypted file; a processing time calculating unit calculating a first processing time in a first processing mode and a second processing time in a second processing mode in accordance with CPU performance information about the image forming apparatus and the authorization management server, information about an allocation of the memory to a rasterization process, the file information, and the rasterization complexity, the first processing mode being a mode where the image forming apparatus performs a decryption process and a rasterization process in parallel, the second processing mode being a mode where the authorization management server performs a decryption process and the image forming apparatus performs a rasterization process; and a decryption destination determining unit comparing the first processing time and the second processing time, and, in accordance with a result of the comparison, determining whether the image forming apparatus or the authorization management server is to perform a decryption process. ### Claim 2 (depends on 1) The encrypted file printing system according to claim 1, wherein the file information includes a file type and an object type of the print file, and the complexity calculating unit calculates the rasterization complexity in accordance with the file type and the object type. ### Claim 3 (depends on 1) The encrypted file printing system according to claim 1, wherein the file information includes the number of pages in the print file, and the processing time calculating unit calculates a first rasterization time in the first processing mode and a second rasterization time in the second processing mode, in accordance with the number of pages, the rasterization complexity, and a standard rasterization time corresponding to the allocation of the memory. ### Claim 4 (depends on 3) The encrypted file printing system according to claim 3, wherein the file information includes a file size of the print file, and the processing time calculating unit calculates a first decryption time in the first processing mode and a second decryption time in the second processing mode, in accordance with the file size. ### Claim 5 (depends on 4) The encrypted file printing system according to claim 4, wherein the processing time calculating unit calculates the first processing time by combining the first rasterization time, the first decryption time, and a time required for obtaining the decryption key from the authorization management server, and calculates the second processing time by combining the second rasterization time, the second decryption time, a time required for transmitting the encrypted file to the authorization management server, and a time required for receiving the decrypted print file from the authorization management server. ### Claim 6 (depends on 1) The encrypted file printing system according to claim 1, wherein the processing time calculating unit increases the allocation of the memory to the rasterization process in the second processing mode to a larger amount than the allocation of the memory to the rasterization process in the first processing mode. ### Claim 7 An encrypted file printing method implemented in a system in which a client terminal that generates a print file, an authorization management server that manages authorization of the print file, and an image forming apparatus that performs printing of the print file are connected by a communication network, the encrypted file printing method comprising: the authorization management server authorizing the print file in response to an authorization request from the client terminal, generating an encryption key for encrypting the print file, and transmitting the encryption key to the client terminal; the client terminal receiving the encryption key from the authorization management server, creating an encrypted file by encrypting the print file using the encryption key, adding file information indicating a structure of the print file as metadata to the encrypted file, and transmitting the encrypted file to the image forming apparatus; the image forming apparatus receiving the encrypted file, and reading the file information added to the encrypted file and calculating a rasterization complexity in the image forming apparatus in accordance with the file information before the encrypted file is decrypted; calculating a first processing time in a first processing mode and a second processing time in a second processing mode in accordance with CPU performance information about the image forming apparatus and the authorization management server, information about an allocation of a memory to a rasterization process, the file information, and the rasterization complexity, the first processing mode being a mode where the image forming apparatus performs a decryption process and a rasterization process in parallel, the second processing mode being a mode where the authorization management server performs a decryption process and the image forming apparatus performs a rasterization process; and comparing the first processing time and the second processing time, and, in accordance with a result of the comparison, determining whether the image forming apparatus or the authorization management server is to perform a decryption process; the authorization management server transmitting a decryption key for decrypting the encrypted file when receiving an authorization check request from the image forming apparatus, and decrypting the encrypted file and transmitting the decrypted print file to the image forming apparatus when receiving the encrypted file from the image forming apparatus; and the image forming apparatus performing a rasterization process on the print file decrypted by the image forming apparatus or the authorization management server. ### Claim 8 (depends on 7) The encrypted file printing method according to claim 7, wherein the file information includes a file type and an object type of the print file, and the image forming apparatus calculates the rasterization complexity in accordance with the file type and the object type. ### Claim 9 (depends on 7) The encrypted file printing method according to claim 7, wherein the file information includes the number of pages in the print file, and the image forming apparatus calculates a first rasterization time in the first processing mode and a second rasterization time in the second processing mode, in accordance with the number of pages, the rasterization complexity, and a standard rasterization time corresponding to the allocation of the memory. ### Claim 10 (depends on 9) The encrypted file printing method according to claim 9, wherein the file information includes a file size of the print file, and the image forming apparatus calculates a first decryption time in the first processing mode and a second decryption time in the second processing mode, in accordance with the file size. ### Claim 11 (depends on 10) The encrypted file printing method according to claim 10, wherein the image forming apparatus calculates the first processing time by combining the first rasterization time, the first decryption time, and a time required for obtaining the decryption key from the authorization management server, and calculates the second processing time by combining the second rasterization time, the second decryption time, a time required for transmitting the encrypted file to the authorization management server, and a time required for receiving the decrypted print file from the authorization management server. ### Claim 12 (depends on 7) The encrypted file printing method according to claim 7, wherein the image forming apparatus increases the allocation of the memory to the rasterization process in the second processing mode to a larger amount than the allocation of the memory to the rasterization process in the first processing mode. ### Claim 13 A non-transitory recording medium storing a computer readable encrypted file print control program to be executed in an image forming apparatus in a system in which a client terminal that generates a print file, an authorization management server that manages authorization of the print file, and the image forming apparatus that performs printing of the print file are connected by a communication network, the encrypted file print control program causing a control unit of the image forming apparatus to perform: a first process to receive, from the client terminal, an encrypted file generated by encrypting the print file with an encryption key generated by the authorization management server, and receive file information added as metadata to the encrypted file, the file information indicating a structure of the print file; a second process to read the file information added to the encrypted file and calculate a rasterization complexity in the image forming apparatus in accordance with the file information before the encrypted file is decrypted; a third process to calculate a first processing time in a first processing mode and a second processing time in a second processing mode in accordance with CPU performance information about the image forming apparatus and the authorization management server, information about an allocation of a memory to a rasterization process, the file information, and the rasterization complexity, the first processing mode being a mode where the image forming apparatus performs a decryption process and a rasterization process in parallel, the second processing mode being a mode where the authorization management server performs a decryption process and the image forming apparatus performs a rasterization process; and a fourth process to compare the first processing time and the second processing time, and, in accordance with a result of the comparison, determine whether the image forming apparatus or the authorization management server is to perform a decryption process. ### Claim 14 (depends on 13) The non-transitory recording medium storing a computer readable encrypted file print control program according to claim 13, wherein the file information includes a file type and an object type of the print file, and, in the second process, the rasterization complexity is calculated in accordance with the file type and the object type. ### Claim 15 (depends on 13) The non-transitory recording medium storing a computer readable encrypted file print control program according to claim 13, wherein the file information includes the number of pages in the print file, and, in the third process, a first rasterization time in the first processing mode and a second rasterization time in the second processing mode are calculated in accordance with the number of pages, the rasterization complexity, and a standard rasterization time corresponding to the allocation of the memory. ### Claim 16 (depends on 15) The non-transitory recording medium storing a computer readable encrypted file print control program according to claim 15, wherein the file information includes a file size of the print file, and, in the third process, a first decryption time in the first processing mode and a second decryption time in the second processing mode are calculated in accordance with the file size. ### Claim 17 (depends on 16) The non-transitory recording medium storing a computer readable encrypted file print control program according to claim 16, wherein, in the third process, the first processing time is calculated by combining the first rasterization time, the first decryption time, and a time required for obtaining the decryption key from the authorization management server, and the second processing time is calculated by combining the second rasterization time, the second decryption time, a time required for transmitting the encrypted file to the authorization management server, and a time required for receiving the decrypted print file from the authorization management server. ### Claim 18 (depends on 13) The non-transitory recording medium storing a computer readable encrypted file print control program according to claim 13, wherein, in the third process, the allocation of the memory to the rasterization process in the second processing mode is increased to a larger amount than the allocation of the memory to the rasterization process in the first processing mode.