©2008 TOSHIBA TEC CORPORATION All rights reserved
System Software
Security Target
22 July 2008
Ver 3.3
This document is a translation of the evaluated and certified security target written in Japanese.
©2006 TOSHIBA TEC CORPORATION All rights reserved
Table of Contents
1. SECURITY TARGET INTRODUCTION................................................................................................ 1
1.1 ST Identification............................................................................................................................... 1
1.2 ST Overview...................................................................................................................................... 1
1.3 CC Conformance............................................................................................................................... 1
1.4 Terms and Abbreviations ................................................................................................................. 2
1.5 Trademark Notice............................................................................................................................. 3
2. TOE DESCRIPTION ............................................................................................................................... 4
2.1 Product Type and Usage Environment ........................................................................................... 4
2.2 Product Functions and TOE............................................................................................................. 6
2.2.1 Features in Normal Mode and TOE ......................................................................................... 6
2.2.1.1 e-STUDIO General Functions in Normal Mode................................................................... 6
2.2.1.2 Security Functions in Normal Mode (Data Erasing Function) ........................................... 7
2.2.2 Functions in Self-diagnostic Mode and TOE............................................................................ 8
2.2.2.1 e-STUDIO General Functions in Self-diagnostic Mode ....................................................... 8
2.2.2.2 Security Functions in Self-diagnostic Mode ......................................................................... 8
2.3 TOE-related Personnel..................................................................................................................... 8
2.3.1 e-STUDIO Users........................................................................................................................ 8
2.3.2 e-STUDIO Administrators........................................................................................................ 8
2.3.3 Service Engineers...................................................................................................................... 8
2.4 Assets to be Protected....................................................................................................................... 9
3. TOE SECURITY ENVIRONMENT ...................................................................................................... 10
3.1 Assumptions.................................................................................................................................... 10
3.2 Threats............................................................................................................................................ 10
3.3 Organizational Security Policies.................................................................................................... 10
4. SECURITY OBJECTIVES .................................................................................................................... 11
4.1 Security Objectives for the TOE .................................................................................................... 11
4.2 Security Objectives for the Environment ...................................................................................... 11
5. IT SECURITY REQUIREMENTS ........................................................................................................ 12
5.1 TOE Security Requirements .......................................................................................................... 12
5.1.1 TOE Security Functional Requirements ................................................................................ 12
5.1.2 TOE Security Assurance Requirement .................................................................................. 12
5.1.3 Minimum Strength of Function Declaration.......................................................................... 13
5.2 Security requirements for the IT environment............................................................................. 13
6. TOE SUMMARY SPECIFICATION ..................................................................................................... 14
6.1 TOE Security Functions................................................................................................................. 14
6.1.1 TOE Security Functions.......................................................................................................... 14
6.1.2 Security Mechanism................................................................................................................ 15
6.1.3 Strength of Function Statement............................................................................................. 15
6.2 Assurance Measures....................................................................................................................... 15
7. PROTECTION PROFILE (PP) CLAIMS .............................................................................................. 16
8. RATIONALE.......................................................................................................................................... 16
8.1 Security Objectives Rationale ........................................................................................................ 16
8.1.1 Necessity of Security Objectives ............................................................................................. 16
8.1.2 Sufficiency of Security Objectives........................................................................................... 16
8.2 Security Requirements Rationale.................................................................................................. 17
8.2.1 Necessity of Security Functional Requirements.................................................................... 17
8.2.2 Sufficiency of Security Functional Requirements.................................................................. 17
8.2.3 Rational for Dependencies of Security Functional Requirements ........................................ 17
8.2.4 Mutually Supportive Security Requirements ........................................................................ 17
8.2.5 Validity of Minimum Strength of Function............................................................................ 18
8.2.6 Rationale for Security Assurance Requirements................................................................... 18
8.3 TOE summary specification rationale........................................................................................... 18
8.3.1 Necessity of Security Functions.............................................................................................. 18
8.3.2 Sufficiency of Security Functions ........................................................................................... 18
8.3.3 Rationale for Strength Of Function........................................................................................ 19
©2006 TOSHIBA TEC CORPORATION All rights reserved
8.3.4 Rationale for Assurance Measures ......................................................................................... 19
8.4 PP Claim rationale ......................................................................................................................... 20
©2006 TOSHIBA TEC CORPORATION All rights reserved
1
1. SECURITY TARGET INTRODUCTION
This chapter describes security target (hereinafter referred to as “ST”) identification information, overview of the ST,
conformance to the Common Criteria for Information Technology Security Evaluation (hereinafter referred to as “CC”),
terms, abbreviations, and trademarks and registered trademarks used in this document.
1.1 ST Identification
Information to identify this ST is as described below:
ST Title : e-STUDIO520/600/720/850, e-STUDIO523/603/723/853 System Software Security
Target
ST Version : Ver3.3
Publication Date : 22 July 2008
Authors of ST : Document Processing & Telecommunication Systems Company,
TOSHIBA TEC CORPORATION
TOE Identification
[Japanese] : e-STUDIO520/600/720/850, e-STUDIO523/603/723/853 System Software
[English] : System Software for e-STUDIO520/600/720/850, e-STUDIO523/603/723/853
TOE Version : V2.0
Authors of TOE : Document Processing & Telecommunication Systems Company,
TOSHIBA TEC CORPORATION
Assurance Level : EAL3
Keywords : Digital multi function device，MFP，e-STUDIO，GP-1060，Data Delete Function，
Data Overwrite，TOSHIBA TEC CORPORATION
CC Identification : Common Criteria for Information Technology Security Evaluation Version 2.3
CCIMB Interpretations (as of August 2005)
Evaluation Methodology : Common Methodology for Information Technology Security Evaluation Version 2.3
CCIMB Interpretations (as of August 2005)
1.2 ST Overview
The TOE which this ST defines is the control software for the TOSHIBA TEC CORPORATION’s MFP, “the e-
STUDIO520/600/720/850 and the e-STUDIO523/603/723/853.” The TOE is enabled when the security functions of
the e-STUDIO are activated by the optional product GP-1060.
The MFP is a digital multi function device which inputs and processes user documents. Its main functions include
copying, printing, faxing, and the e-Filing Box/shared folder feature.
When these functions are used, user document data input into the MFP is temporarily written into the HDD and deleted
after the processing is finished. However, the deletion in the FAT file system does not erase the data permanently,
leaving them recoverable. This is also the case with the deletion of the user document data saved in the e-Filing
Box/shared folder.
The TOE ensures that the deletion of the user document data written into the HDD while using the MFP functions
erases them permanently from the HDD in an unrecoverable manner. In addition, before the HDD is disposed of or
replaced, a service engineer erases the data in the all memory areas of the e-Filing Box/shared folder, permanently
erasing all the document data in the HDD.
1.3 CC Conformance
This ST conforms to the following CC specifications:
• CC Version 2.3, Part 2 conformant
• CC Version 2.3, Part 3 conformant
• Assurance level: EAL 3 conformant
• There are no Protection Profiles (PPs) to which this ST is conformant.
©2006 TOSHIBA TEC CORPORATION All rights reserved
2
1.4 Terms and Abbreviations
The following terms and abbreviations are used in this ST.
<CC-related abbreviations>
• CC Common Criteria
• EAL Evaluation Assurance Level
• PP Protection Profile
• ST Security Target
• TOE Target Of Evaluation
• SOF Strength Of Function
• TSF TOE Security Function
• TSP TOE Security Policy
• TSC TSF Scope of Control
<TOE-related terms and abbreviations>
• MFP
Multi Function Peripherals (Digital multi function device), a single multi-functional peripheral device which
integrates several functions mainly copying, scanning, printing, and faxing.
• e-STUDIO
MFPs. In this ST, it refers to the e-STUDIO520/600/720/850 and the e-STUDIO523/603/723/853 (e-
STUDIO520, e-STUDIO600, e-STUDIO720, e-STUDIO850, e-STUDIO523, e-STUDIO603, e-STUDIO723,
and e-STUDIO853).
• e-STUDIO General Functions
Copying, scanning, printing, faxing, and the e-Filing Box/shared folder functions that are installed into the e-
STUDIO and available for general users.
• Job
A unit used for the processing of the General Functions. The user document data temporarily written into
the HDD for the processing during a job or when a job is finished (or cancelled) are permanently erased by
the TSF.
• User document
Documents that users possess, such as Word, Excel, PDF, and text documents and JPEG images.
• User document data
Computerized user documents which exist in the MFP. This includes user documents computerized and
input by the scanner, computerized documents that the MFP has received, and the data generated by
processing them in the MFP.
• Deletion
To release the resources and make data unavailable for users.
• Erasing
To erase data without leaving traces.
• Perfect erasing
To permanently erase data to prevent the reuse of user document data by overwriting the areas for the data to
be deleted with meaningless data.
• TopAccess
A web-based job/device management tool which enables users to obtain information about MFP via the
Internet and use two types of web sites, for users and for administrators.
• e-Filing Box
The location where users save user document data. After saving data, users can refer to, print, or edit them
with the control panel or the TopAccess. When the file saving period expires, the saved user document data
are deleted. There are two types of e-Filing Boxes: public boxes, which have no access limitations, and user
©2006 TOSHIBA TEC CORPORATION All rights reserved
3
boxes, which users can create after setting a password.
• Shared folder
The location where users can save user document date in file formats such as JPEG and PDF and obtain files
from client PCs on the Internet. When the file saving period expires, the saved user document data are
deleted.
• Internet fax
Communicates through LAN network using Emails to send original documents in TIFF-FX (Profile S) -
format attached files. One of its advantages is less communications cost and higher resolution than normal
facsimile. Data can be sent and received via the Internet fax between compatible models. In addition,
documents and images can be sent from a PC and received by a compatible model as the Internet fax. When
they are sent from a compatible model to a PC, they are received as Emails by the PC. When the main unit
receives the Internet fax, it automatically output it just as normal facsimile.
• WS scanning
WS (Web Service) scanning is a function that performs scanning operations with Windows Vista computers
via networks using functions of the computer. Images scanned by the main unit can be saved into a
computer. In addition, images can be acquired by sending a scanning request from a WIA (Windows
Imaging Acquisition) Scan Driver-compatible application to the main unit.
• GP-1060
A product installed in the e-STUDIO to enable the Data Erasing Function, a security function of the System
Software
1.5 Trademark Notice
• VxWorks is a registered trademark or trademark of Wind River Systems, Inc.
• The formal name of Windows Vista is Microsoft Windows Vista Operating System.
• Microsoft, Windows, Windows NT, and the names and the product names of other Microsoft products are
registered trademarks or trademarks in USA or other countries of Microsoft Corporation, USA.
• Firefox and Thunderbird are registered trademarks or trademarks in USA or other countries of Mozilla
Foundation, USA.
• All other product names mentioned in this ST may be trademarks or registered trademarks of their respective
owners.
©2006 TOSHIBA TEC CORPORATION All rights reserved
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2. TOE DESCRIPTION
This chapter describes the product type, usage environment, product configuration, functions, and threads regarding the
e-STUDIO520/600/720/850 and the e-STUDIO523/603/723/853.
2.1 Product Type and Usage Environment
This ST defines eight types of MFPs, the e-STUDIO520, e-STUDIO600, e-STUDIO720, e-STUDIO850, e-
STUDIO523, e-STUDIO603, e-STUDIO723, and e-STUDIO853, each having different print speed. The TOE is the
common control software among them.
As shown in Figure 2.1 below, the e-STUDIO is used as a terminal to send/receive data to/from facsimiles, a terminal to
send Email to Email servers, and a remote printer for remote PCs in network environments as well as it is installed in
general offices as a standalone copier.
Figure 2.1 Use of the e-STUDIO in Network Environment
The security functions, optional functions of the e-STUDIO can be enabled when a service engineer connects the
security enabler GP-1060 to the e-STUDIO. The security functions of the TOE are always enabled.
The enabled security functions erase user document data in an unrecoverable manner when the user deletes them during
a job specified by the user or after the job is finished (or cancelled).
Using e-STUDIO General Functions temporarily stores the user document data from the scanner or the LAN/FAX/USB
lines into the HDD of the MFP. Then, printing, faxing, or saving into the e-Filing Box/shared holder is performed
using the data. The user document data temporarily stored in the process will be deleted as soon as they become
unnecessary.
If the security functions are not enabled then, the file is deleted by the file delete function provided by OS. In this case,
only the file area pointer of the FAT32 (File Allocation Table) managed by OS is cleared, and the area with the user
document data that the e-STUDIO user never imagines exist in the HDD still remains in the e-STUDIO. Furthermore,
past data exist as remnant magnetism even after they are overwritten with new data. Therefore, an attacker with
knowledge of OS and data recovering tools can remove the HDD and then read the reference of the actual data, which
have lost only the pointer, and the remnant magnetism of the data and retrieve information, posing a huge threat.
Similarly, when the data in the e-Filing Box/shared folder are deleted, a fear exists that the data that the user believes
are deleted can be read.
The data erasing function, a security function in normal mode of the TOE (2.2.1.2 Security Functions in Normal Mode)
permanently erases the deleted user document data. As long as the security function is enabled, erasing residual data
does not require special operations by users.
Mail
server
PC
PSTN
FAX
LAN
Internet
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In addition, overwrite erasing compulsion execution processing of the security functions in self-diagnostic mode
(2.2.2.2 Security Functions in Self-Diagnostic Mode) collectively and permanently erase the user document data left
saved in the e-Filing Box/shared folder when the HDD is disposed of or replaced. As this function works in self-
diagnostic mode, it is enabled by a service engineer.
Hardware Configuration Specification
e-STUDIO520/600/720/850
e-STUDIO523/603/723/853
e-STUDIO520/523: 52 sheets/min.
e-STUDIO600/603: 60 sheets/min.
e-STUDIO720/723: 72 sheets/min.
e-STUDIO850/853: 85 sheets/min.
Copy/print speed on A4-size or
LETTER-size papers
GP-1060 USB interface
Table 2.1-1 e-STUDIO Hardware Configuration
Software Configuration Function
System Software V2.0
System Software for controlling
the e-STUDIO520/600/720/850 and
the e-STUDIO523/603/723/853
UI data (Optional languages)
Japanese: V055.000 2
American English: V062.000 3
European English: V058.000 4
Language data for each destination (nation)
VxWorks 5.5 OS
Table 2.1-2 e-STUDIO Software Configuration
Software such as Printer Driver, Fax Driver, Web Browser, or Mailer is required in PC, to use in normal mode of 2.2.1
in Figure 2.1 configuration.
• Printer Driver
e-STUDIO850 Series PrinterDriver Ver 4.4.63.0
• Fax Driver
e-STUDIO850 Series N/W-Fax Driver Ver 4.9.60.0
• Browser
InternetExplorer ver6.0 sp1 or Firefox ver2.0.0.14
• Mailer
AL-Mail32 Version1.13 or Thunderbird ver2.0.0.14
• WIA Scan Driver Application
Windows Fax and Scan Version 6.0
©2006 TOSHIBA TEC CORPORATION All rights reserved
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2.2 Product Functions and TOE
This product is a digital multi function device in which e-STUDIO General Functions, that is, copying, scanning,
printing, faxing, and the e-Filing Box/shared folder functions are installed.
The TOE is software for the e-STUDIO which resides in its ROM and conducts overall control on it.
The e-STUDIO starts in normal mode, where users operate it.
In normal mode, the e-STUDIO General Functions and the security functions in normal mode (Refer to Section 2.2.1.2.)
are available.
Besides the normal mode, the e-STUDIO offers a self-diagnostic mode where service engineers perform maintenance
services. When the e-STUDIO starts in this mode, the e-STUDIO General Functions and the security function in
normal mode are disabled. In self-diagnostic mode, only the security function in this mode (Refer to Section 2.2.2.2)
is available.
2.2.1 Features in Normal Mode and TOE
Figure 2.2.1 shows the configuration of the e-STUDIO in normal mode. User document data exist only in the work
area of the HDD, specified e-Filing Boxes, and shared folder.
Overall System Software shown in Figure 2.2.1, excluding the operation system, is the TOE of this ST in normal mode.
Figure 2.2.1 Product Configuration in Normal Mode
2.2.1.1 e-STUDIO General Functions in Normal Mode
(1) Processing GP-1060 Installation Information
This process checks whether or not the GP-1060 is installed.
In order to make the e-STUDIO users aware that the Data Erasing Function is available, an icon representing
data erasing and the TOE version are displayed on the “Setting/Registration” screen of the control panel.
(2) Copying
When the START button is pressed with the copying function selected, this function scans user document data
using the scanner and writes the scanned data into the work area of the HDD.
Then, this function reads the user document data in the work area and performs both or either of the following
processings:
y Outputs the user document data to the printer.
TOE Storage for assets to be protected
PSTN
(FAX)
GP-1060
Scanner
e-STUDIO General Functions (Job Management)
Data Erasing Function
Printer
LAN Line
(PC)
Initialization Processing (System Administration)
Control Panel
Display
Overwrite Processing
Registration of Overwrite Processing
Copying Scanning
Printing FAX
Transmission
FAX
Reception
Processing for
e-Filing Box/
shared folder
Processing GP-1060 installation information
OS (VxWorks 5.5)
User document data
deleted by OS’s
delete function
HDD
USB
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y Saves the user document data in an e-Filing Box or a shared folder in the HDD specified by the e-STUDIO
user.
(3) Printing
This function receives user document data via a LAN line (PC) or a USB, or reads user document data in an
e-Filing Box, and writes the data in the work area of the HDD.
Then, this function reads the user document data in the work area and performs both or either of the following
processings:
y Outputs the user document data to the printer.
y Saves the user document data in an e-Filing Box or a shared folder in the HDD specified by the e-STUDIO
user.
(4) Scanning
When the START button is pressed while the SCAN button is being held down, this process scans user document
data using the scanner and performs both or either of the following processings:
y Saves the user document data in an e-Filing Box or a shared folder in the HDD specified by the e-STUDIO
user or sends the data to computer(s) specified with WS scanning.
y Sends Email to a destination specified by the e-STUDIO user.
(5) Fax transmission
When the START button is pressed while the FAX button is being held down, this function scans user document
data using the scanner and writes the scanned data in the work area of the HDD.
Then, this function reads the user document data in the work area and sends the data to facsimile(s). The data
can also be saved in a shared folder.
(6) Fax reception
This function receives user document data from a facsimile and writes the data in the work area of the HDD.
Then, this function reads the user document data in the work area and performs both or either of the following
processings:
y Outputs the user document data to the printer.
y Saves the user document data in an e-Filing Box or a shared folder in the HDD specified by the e-STUDIO
user.
(7) Processing for e-Filing Box and shared folder
This function deletes user document data which was saved in an e-Filing Box or a shared folder in the HDD,
when commanded by the control panel or from a PC via a LAN line.
2.2.1.2 Security Functions in Normal Mode (Data Erasing Function)
There are two security functions in normal mode: Data Overwrite registration processing and Data Overwrite
processing. These two functions are altogether called the data erasing function.
(1) Data Overwrite registration processing
The Data Overwrite registration processing is started up when user document data are deleted in the processings
of the e-STUDIO General Functions (2) to (7). In this processing, only the path for the user document data with a
deletion request is moved to the trash box (renamed). This processing makes the deleted files those for the Data
Overwrite processing.
(2) Data Overwrite process
This function checks if user document data has been registered with the trash box and, if any has been registered,
permanently erases the storing area. While this processing is being executed, the message “ERASING DATA”
is displayed on the control panel.
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2.2.2 Functions in Self-diagnostic Mode and TOE
Figure 2.2.2 shows the configuration of the e-STUDIO in self-diagnostic mode. Overall System Software shown in
Figure 2.2.2, excluding the operation system, is the TOE of this ST in self-diagnostic mode.
Figure 2.2.2 Product Configuration in Self-diagnostic Mode
2.2.2.1 e-STUDIO General Functions in Self-diagnostic Mode
Although e-STUDIO General Functions in self-diagnostic mode have the settings for maintenance and display the
device information, only the security function-related processings shown below are described here.
• Processing GP-1060 Installation Information
This process checks whether or not the GP-1060 is installed. Although whether the Data Erasing Function is
enabled is not displayed on the screen for service engineers, the security functions in self-diagnostic mode
described in 2.2.1.4 can be used if they are enabled.
2.2.2.2 Security Functions in Self-diagnostic Mode
• Forcible Data Overwrite processing
It collectively and permanently erases all areas where user document data which are stored in HDD are written.
2.3 TOE-related Personnel
The following describes personnel required for operating the TOE.
2.3.1 Users
Users who utilize the e-STUDIO General Functions of the e-STUDIO
2.3.2 e-STUDIO Administrators
Administrators make each setting of the TOE’s General Functions (including copy, network, and fax settings) and ask
service engineers to execute the forcible Data Overwrite function to the HDD. Note that they do not manage the
TOE’s security functions.
2.3.3 Service Engineers
Service engineers perform service maintenance operations such as installation of the e-STUDIO (including installation
of the GP1060).
Upon request from the e-STUDIO administrator, a service engineer operates the TOE in self-diagnostic mode, then
TOE Storage for assets to be protected
GP-1060 Data Erasing Function
Initialization Processing
(System Administration)
Control Panel
Display
Forcible Data Overwrite
Processing GP-1060
installation information
OS (VxWorks 5.5)
e-Filing Box
HDD
Shared Folder
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executes the forcible Data Overwrite function to collectively and permanently erases all HDD areas of the
e-STUDIO where user document data are stored.
2.4 Assets to be Protected
The assets to be protected in normal or self-diagnostic mode are described below.
• Assets to be protected in normal mode
The data remaining magnetically in the HDD after the deletion of user document data are the assets to be
protected. The assets to be protected are generated when the e-STUDIO deletes user document data during the
job specified by the user or after it is finished (or cancelled).
Note that the remaining data from the user document data deleted in the following processings are excluded
from the protection target:
[1] Fax reception
Since it can be assumed that facsimile senders perform facsimile transmission from a site far away from the
TOE and have no means to confirm that the transmitted facsimile data have been erased by the security
functions, these data are excluded from the protection target.
[2] Automatic deletion after the file saving period expires in the e-Filing Box/shared folder
If the saving period (days) is set, user document data are deleted by the TOE when the period expires. Since
it can not be assumed that users will confirm the security functions erase the data every time they are
automatically deleted, these data are excluded form the protection target.
• Assets to be protected when the HDD is disposed of or replaced
The user document data remaining in the HDD of the e-STUDIO to be disposed of or to be replaced are the
assets to be protected.
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3. TOE SECURITY ENVIRONMENT
This chapter describes the assumptions, threats, and organizational security policies for the TOE.
3.1 Assumptions
There are no assumptions.
3.2 Threats
The following are the potential threats to the e-STUDIO.
• T.TEMPDATA_ACCESS
A malicious e-STUDIO user or non-privileged user may attempt to retrieve user documents by using off-the-
shelf tools to recover and decode user document data deleted from the HDD of the e-STUDIO.
• T.STOREDATA_ACCESS
A malicious e-STUDIO user or non-privileged user may attempt to retrieve user documents from the HDD of
the e-STUDIO by using off-the-shelf tools.
3.3 Organizational Security Policies
There are no organizational security policies for the TOE.
©2006 TOSHIBA TEC CORPORATION All rights reserved
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4. SECURITY OBJECTIVES
This chapter describes security objectives for the TOE and security objectives for the environment.
4.1 Security Objectives for the TOE
The following are the security objectives for the TOE.
• O.TEMPDATA_OVERWRITE
The TOE must permanently erase the areas in the HDD of the e-STUDIO, from which user document data were
deleted, in order to prevent such areas from being recovered or decoded.
• O.STOREDATA_OVERWRITE
The TOE must be deleted collectively by forcible data overwriting, not to recover or decode user document
data from the HDD of the e-STUDIO which is disposed of or replaced.
4.2 Security Objectives for the Environment
The following are the security objective for the environment.
• OE.OVERWRITE_COMPLETE
When collecting printout from e-STUDIO, users must make sure that user document data has been permanently
erased from the HDD by checking that the “ERASING DATA” message on the LCD display, if displayed on
the control panel, has disappeared properly.
• OE.HDD_ERASE
e-STUDIO administrators must ask service engineers to execute the forcible Data Overwrite function on the
HDD to permanently erase all user document data, when e-STUDIO is disposed of or the HDD is replaced.
©2006 TOSHIBA TEC CORPORATION All rights reserved
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5. IT SECURITY REQUIREMENTS
This chapter describes the security requirements for the TOE and the IT environment.
5.1 TOE Security Requirements
5.1.1 TOE Security Functional Requirements
The following are the security functional requirements for the TOE.
• FDP_RIP.1 Subset residual information protection
Hierarchical to: No other components.
FDP_RIP.1.1 The TSF shall ensure that any previous information content of a resource is made
unavailable upon the [selection: allocation of the resource to, deallocation of the
resource from] the following objects: [assignment: list of objects].
[assignment: list of objects]
The areas in the HDD of the e-STUDIO from which user document data was deleted by
the operation system’s file delete function
Dependencies: No dependencies.
• FDP_RIP.2 Full residual information protection
Hierarchical to: FDP_RIP.1
FDP_RIP.2.1 The TSF shall ensure that any previous information content of a resource is made
unavailable upon the [selection: allocation of the resource to, deallocation of the
resource from] all objects.
Dependencies: No dependencies.
• FPT_RVM.1 Non-bypassability of the TSP
Hierarchical to: No other components.
FPT_RVM.1.1 The TSF shall ensure that TSP enforcement functions are invoked and succeed before
each function within the TSC is allowed to proceed.
Dependencies: No dependencies.
5.1.2 TOE Security Assurance Requirement
The target assurance level for the TOE is EAL3. The security assurance components of the TOE are as described
below:
• ACM_CAP.3 Authorization controls
• ACM_SCP.1 TOE CM coverage
• ADO_DEL.1 Delivery procedures
• ADO_IGS.1 Installation, generation, and start-up procedures
• ADV_FSP.1 Informal functional specification
• ADV_HLD.2 Security enforcing high-level design
• ADV_RCR.1 Informal correspondence demonstration
• AGD_ADM.1 Administrator guidance
• AGD_USR.1 User guidance
• ALC_DVS.1 Identification of security measures
• ATE_COV.2 Analysis of coverage
• ATE_DPT.1 Testing: high-level design
• ATE_FUN.1 Functional testing
• ATE_IND.2 Independent testing - sample
• AVA_MSU.1 Examination of guidance
• AVA_SOF.1 Strength of TOE security function evaluation
• AVA_VLA.1 Developer vulnerability analysis
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5.1.3 Minimum Strength of Function Declaration
The minimum Strength of Function (SOF) claim for the TOE is SOF-basic.
There are no probabilistic or permutational mechanisms in the TOE that the SOF claims.
5.2 Security requirements for the IT environment
There are no security functional requirements for the IT environment.
©2006 TOSHIBA TEC CORPORATION All rights reserved
14
6. TOE SUMMARY SPECIFICATION
This chapter describes the TOE summary specification.
6.1 TOE Security Functions
As Table 6.1-1 below shows, the TOE security functions described in Section 6.1.1 satisfy the security functional
requirements described in Section 5.1.1.
FDP_RIP.1 FDP_RIP.2 FPT_RVM.1
SF.TEMPDATA_OVERWRITE ✓ ✓
SF.STOREDATA_OVERWRITE ✓ ✓
Table 6.1-1 Correspondences between TOE Security Functions and Security Functional Requirements
6.1.1 TOE Security Functions
The following describes the TOE security functions.
SF.TEMPDATA_OVERWRITE
The TOE must provide the following protection for user document data deleted from the HDD of the e-STUDIO, erase
the user document data registered with the trash box, and prevent the deleted user document data from being recovered
or decoded.
[Residual Information Protection]
• In normal mode, this protection registers it with the trash box where user document data, deleted from the HDD
of the e-STUDIO, is to be stored.
• In addition, the protection permanently overwrites it which was registered with the trash box where the user
document data, deleted from the HDD of the e-STUDIO, are stored.
(FDP_RIP.1)
Also, in order to prevent this function from being bypassed, the TOE must always execute
SF.TEMPDATA_OVERWRITE whenever user document data is used by the e-STUDIO General Functions, by
permanently erasing the allocated areas in the trash box where the user document data, deleted from the HDD of
the e-STUDIO, are stored and by deallocating such storage areas.
(FPT_RVM.1)
SF.STOREDATA_OVERWRITE
The TOE must provide the following protection for all user document data to be collectively deleted from the HDD of
the e-STUDIO by forcible data overwrite processing, and prevent the deleted user document data from being recovered
or decoded.
[Residual Information Protection]
• In self-diagnostic mode, this protection collectively and permanently overwrites all areas of the HDD.
(FDP_RIP.2)
Also, in order to prevent this function from being bypassed, the TOE must execute
SF.STOREDATA_OVERWRITE from the operation panel to overwrite all areas of the HDD and deallocate such
areas.
(FPT_RVM.1)
©2006 TOSHIBA TEC CORPORATION All rights reserved
15
6.1.2 Security Mechanism
The table below shows the security mechanism referred to in this ST and used by the TOE security functions.
Security Mechanism Security Functions
DoD5220.22-M
SF.TEMPDATA_OVERWRITE
SF.STOREDATA_OVERWRITE
Table 6.1 Security Mechanism and TOE Security Functions
DoD5220.22-M-compliant: 0x00 Fill + 0xFF Fill + random number Fill + validation
6.1.3 Strength of Function Statement
The TOE contains no security functions that are realized by a non-cryptographic and probabilistic or permutational
mechanisms.
6.2 Assurance Measures
The documents provided as security assurance measures of the TOE which satisfy the security assurance requirements
are as described below:
Assurance
Class
Assurance
Components
Documents and TOE
ACM
Configuration
management
ACM_CAP.3
ACM_SCP.1
Configuration List of System Software for
the e-STUDIO520/600/720/850 and the e-STUDIO523/603/723/853*
Configuration Management Plan for System Software for
the e-STUDIO520/600/720/850 and the e-STUDIO523/603/723/853*
ADV
Development
ADV_FSP.1
ADV_HLD.2
Functional specification*/High-level design*
ADV_RCR.1 Representation correspondence*
ALC
Lyfe cycle definition
ALC_DVS.1 Development security*
ATE
Tests
ATE_COV.2
ATE_DPT.1
ATE_FUN.1
ATE_IND.2
Functional tests*
TOE
AVA
Vulnerability
assessment
AVA_MSU.1
Quick Start Guide [Japanese]*
Quick Start Guide
AVA_VLA.1
AVA_SOF.1
Vulnerability analysis*
AGD
Guidance documents
AGD_ADM.1
AGD_USR.1
Quick Start Guide [Japanese]*
Quick Start Guide
ADO
Delivery and
operation
ADO_IGS.1
SERVICE MANUAL [Overview]*
SERVICE MANUAL [Service]*
SERVICE MANUAL
SERVICE HANDBOOK
GP-1060 for the e-STUDIO520/600/720/850 and
the e-STUDIO523/603/723/853
ADO_DEL.1
Delivery procedures of the e-STUDIO series’ TOE*
Delivery procedures of the System Software*
Table 6.2-1 Security Assurance Measures and Security Assurance Requirements
Note: An asterisk (*) in the table above indicates the document is available only in Japanese.
Two asterisks (**) in the table above indicate the document is available both in Japanese and English.
Note: The model numbers vary depending on the destination (country) because the models that are not described in a
guidance will not be delivered to the destination (country). (For example, e-STUDIO520 is not described in the
guidance for Japan.)
©2006 TOSHIBA TEC CORPORATION All rights reserved
16
7. PROTECTION PROFILE (PP) CLAIMS
The TOE does not claim conformance to a PP.
8. RATIONALE
This chapter describes the rationale for the security objectives, security requirements, TOE summary specification, and
PP claims.
8.1 Security Objectives Rationale
8.1.1 Necessity of Security Objectives
The table below shows the mapping of security objectives to assumptions and threats and demonstrates that each
security objective for the TOE is effective for at least one of the assumptions and threats.
T.TEMPDATA_ACCESS
T.STOREDATA_ACCESS
O.TEMPDATA_OVERWRITE ✓
OE.OVERWRITE_COMPLETE ✓
O.STOREDATA_OVERWRITE ✓
OE.HDD_ERASE ✓
Table 8.1-1 Security Objectives to Assumptions and Threats
8.1.2 Sufficiency of Security Objectives
This section describes sufficiency of security objectives against the TOE security environment (assumptions and
threats).
• T.TEMPDATA_ACCESS
O.TEMPDATA_OVERWRITE can prevent user document data, deleted from the HDD of the e-STUDIO,
from being recovered and decoded.
OE.OVERWRITE_COMPLETE ensures that O.TEMPDATA_OVERWRITE was successfully performed.
Accordingly, an attack method to T.TEMPDATA_ACCESS is invalidated.
• T.STOREDATA_ACCESS
OE.HDD_ERASE allows e-STUDIO administrators to ask service engineers to execute Data Overwrite
function on the HDD to permanently erase all files from the HDD, when e-STUDIO is disposed of or the HDD
is replaced by protecting user document data of the HDD of e-STUDIO from being decoding or recovered.
O.STOREDATA_OVERWRITE can prevent user document data, all files of which were permanently erased
from the HDD of the e-STUDIO by the forcible Data Overwrite function, from being recovered and decoded.
Accordingly, an attack method to T.STOREDATA_ACCESS is invalidated.
©2006 TOSHIBA TEC CORPORATION All rights reserved
17
8.2 Security Requirements Rationale
8.2.1 Necessity of Security Functional Requirements
The table below shows relations between security functional requirements and security objectives and demonstrates that
each security functional requirement corresponds to at least one security objective.
O.TEMPDATA_OVERWRITE
O.STOREDATA_OVERWRITE
FDP_RIP.1 ✓
FDP_RIP.2 ✓
FPT_RVM.1 ✓ ✓
Table 8.2-1 Correspondences between TOE Security Functional Requirements and TOE Security Objectives
8.2.2 Sufficiency of Security Functional Requirements
This section describes that the functional requirements sufficiently assure the security objectives for the TOE.
• O.TEMPDATA_OVERWRITE
FDP_RIP.1 deletes stored areas of user document data where files are deleted permanently.
FPT_RVM.1 reliably prevents the security functions from being bypassed.
Accordingly, the security objective can be realized, which prevents storage areas for user document data,
deleted from the HDD of the e-STUDIO, from being recovered and decoded.
• O.STOREDATA_OVERWRITE
FDP_RIP.2 deletes all user document data (object) permanently.
FPT_RVM.1 reliably prevents the security functions from being bypassed.
Accordingly, the security objective can be realized, which prevents areas for user document data from the HDD
of the e-STUDIO, from being recovered and decoded.
8.2.3 Rational for Dependencies of Security Functional Requirements
This section describes the rationale for the dependencies of the security functional requirements.
• FDP_RIP.1
There are no dependencies to be satisfied.
• FDP_RIP.2
There are no dependencies to be satisfied.
• FPT_RVM.1
There are no dependencies to be satisfied.
8.2.4 Mutually Supportive Security Requirements
This section describes that the security functional requirements, mutually complement with each other, are protected
against bypass, interference, and deactivation.
Note that FDP_RIP.1 and FDP_RIP.2 do not function simultaneously because each of them functions in different mode.
• FPT_RVM.1 <Non-bypassability>
FPT_RVM.1 ensures that FDP_RIP.1 in normal mode or FDP_RIP.2 in self-diagnostic mode functions without
©2006 TOSHIBA TEC CORPORATION All rights reserved
18
being bypassed.
• <No interference>
It is impossible to externally modify the TOE itself because it resides in the ROM to control overall
e-STUDIO. And, there are no unauthorized subjects which modify the TSF data (information in the trash
box). Therefore, there are preventive measures against interference by unreliable subject and no functional
requirements are required to prevent the security functions from being modified.
• <Prevention of Deactivation>
There are no functions which deactivate the security functions of the TOE.
8.2.5 Validity of Minimum Strength of Function
As it is assumed that attackers’ attack capabilities is low, the appropriate minimum SOF is SOF-basic.
8.2.6 Rationale for Security Assurance Requirements
The TOE is used in general office environments. Therefore, regarding the TOE, opportunities of attack are limited and
low attack capabilities of threat agents can be assumed.
In order to cope with the attacks by the threat agents, security measures, which must be analyzed during the
development of the TOE (systematic analysis and test of design, and security assurance of development environment),
are to be evaluated. Therefore, an appropriate assurance level for the TOE is EAL3.
8.3 TOE summary specification rationale
8.3.1 Necessity of Security Functions
The table below shows relations between TOE security functions and security functional requirements and demonstrates
that each TOE security function corresponds to at least one TOE security functional requirement.
FDP_RIP.1
FDP_RIP.2
FPT_RVM.1
SF.TEMPDATA_OVERWRITE ✓ ✓
SF.STOREDATA_OVERWRITE ✓ ✓
Table 8.3-1 Correspondences between TOE Security Functions and Security Functional Requirements
8.3.2 Sufficiency of Security Functions
This section describes that the security functions fully assure the security functional requirements for the TOE.
• FDP_RIP.1
SF.TEMPDATA_OVERWRITE permanently erases user document data in the HDD of the STUDIO to
ensure that user document data, deleted from the HDD, are no longer available.
Accordingly, residual information protection is assured by SF.TEMPDATA_OVERWRITE.
• FDP_RIP.2
SF.STOREDATA_OVERWRITE collectively and permanently erases all areas of the HDD of the
e-STUDIO including user document data stored there to ensure that all user document data in the HDD are no
longer available.
Accordingly, residual information protection is assured by SF.STOREDATA_OVERWRITE.
• FPT_RVM.1
SF.TEMPDATA_OVERWRITE permanently erases user document data whenever they are deleted from the
HDD of the e-STUDIO.
In addition, SF.STOREDATA_OVERWRITE collectively and permanently erases all user document data
whenever they are deleted from the HDD of the e-STUDIO by forcible data overwrite processing.
©2006 TOSHIBA TEC CORPORATION All rights reserved
19
Accordingly, no-bypassability is assured by SF.TEMPDATA_OVERWRITE and
SF.STOREDATA_OVERWRITE.
8.3.3 Rationale for Strength Of Function
There are no security functions which have probabilistic or permutational mechanisms for which rationale must be
provided.
8.3.4 Rationale for Assurance Measures
This section describes the rationales which demonstrate that security measures for the TOE satisfy the assurance
requirements. Each security assurance requirement to meet EAL3 corresponds documents and TOE which are security
assurance measures.
Such documents and TOE can provide all evidences for the security assurance requirements.
Table 8.3-2 below shows the details of each assurance measure.
Assurance
Class
Assurance
Components
Documents and TOE Descriptions
ACM
Configuration
management
ACM_CAP.3
ACM_SCP.1
・Configuration List of System Software
for
the e-STUDIO520/600/720/850 and
the e-STUDIO523/603/723/853*
・Configuration Management Plan for
System Software for
the e-STUDIO520/600/720/850 and
the e-STUDIO523/603/723/853*
These documents describe the
configuration management method for
the TOE.
Also they describe references and
configuration list for the TOE, CM
plan, and CM system.
ADV
Development
ADV_FSP.1
ADV_HLD.2
Functional specification*/
High-level design*
These documents describe the TOE
security functions (TSF) from the
viewpoint of the behavior of the TSF
and TSF interface, external interfaces
for functions other than the TSF
(functional specifications) and the sub-
system.
In addition, they describe the TSF
structure and interface of the sub-
system (High-level design).
ADV_RCR.1 Representation correspondence*
This document provides analysis
report on relations between security
functions in the summary specification
and the subsystem in the functional
specification/high-level design for the
ST.
ALC
Life Cycle
Definition
ALC_DVS.1 Development security*
This document describes the means for
assuring confidentiality and integrity
of the design and implementation of
the TOE in the development
environment.
ATE
Tests
ATE_COV.2
ATE_DPT.1
ATE_FUN.1
ATE_IND.2
・Functional tests*
・TOE
These documents describe functional
test items and test procedures used for
proving that the TSF functions are as
specified, expected test results, and
actual test results under the above-
mentioned conditions.
©2006 TOSHIBA TEC CORPORATION All rights reserved
20
Assurance
Class
Assurance
Components
Documents and TOE Descriptions
AVA
Vulnerability
assessment
AVA_MSU.1
・Quick Start Guide [Japanese]*
・Quick Start Guide
These documents describe the
procedures to help the TOE users
securely install the product and
software and perform operations.
AVA_VLA.1
Vulnerability analysis*
This document describes the result of
vulnerability analysis to ensure that
obvious security vulnerability found
will not be wrongfully used in TOE
environments.
AVA_SOF.1
This document describes the analysis
result of strength of function for
security mechanisms which have
probabilistic or permutational
mechanisms excluding cryptographic
mechanism for the TOE.
AGD
Guidance
documents
AGD_ADM.1
AGD_USR.1
・Quick Start Guide [Japanese]*
・Quick Start Guide
These documents describe the
procedures to help the TOE users
securely install the product and
software and perform operations.
ADO
Delivery and
operation
ADO_IGS.1
・SERVICE MANUAL [Overview]*
・SERVICE MANUAL [Service]*
・SERVICE MANUAL
・SERVICE HANDBOOK
GP-1060 for
the e-STUDIO520/600/720/850 and
the e-STUDIO523/603/723/853
ADO_DEL.1
・Delivery procedures of the e-STUDIO
series’ TOE*
・Delivery procedures of the System
Software*
Table 8.3-2 List of Security Assurance Measures
Note: An asterisk (*) in the table above indicates the document is available only in Japanese.
Two asterisks (**) in the table above indicate the document is available both in Japanese and English.
Note: The model numbers vary depending on the destination (country) because the models that are not described in a
guidance will not be delivered to the destination (country). (For example, e-STUDIO520 is not described in the
guidance for Japan.)
8.4 PP Claim rationale
There are no Protection Profiles (PPs) to which this ST is conformant.