c12) United States Patent
`Uchida
`
`111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US007124301Bl
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,124,301 B1
`Oct. 17, 2006
`
`(54) DATA PROTECTION METHOD FOR A
`REMOVABLE STORAGE MEDIUM AND A
`STORAGE DEVICE USING THE SAME
`
`(75)
`
`Inventor: Yoshiaki Uchida, Kawasaki (JP)
`
`(73) Assignee: Fujitsu Limited, Kawasaki (JP)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/139,485
`
`(22) Filed:
`
`Aug. 25, 1998
`
`(30)
`
`Foreign Application Priority Data
`
`Nov. 28, 1997
`
`(JP) ............................................. 9-328959
`
`(51)
`
`Int. Cl.
`G06F 11130
`
`(2006.01)
`
`(52) U.S. Cl. ........................................ 713/189; 713/193
`(58) Field of Classification Search ................. 713/193,
`713/163,200,202,165-167,176, 189;380/203;
`711/163; 360/60; 386/94
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`4,864,542 A * 9/1989 Oshima et al ......... 365/189.01
`5,058,162 A
`10/1991 Santon et al .................. 380/25
`5,533,125 A * 7/1996 Bensimon eta!. .......... 7111163
`5,563,947 A * 10/1996 Kikinis ........................ 705/51
`5,644,444 A * 7/1997 Braithwaite eta!. .......... 360/60
`10/1997 Blakley, III eta!. ............ 380/4
`5,677,952 A
`
`5,796,943 A * 8/1998 Fujioka ...................... 713/202
`
`FOREIGN PATENT DOCUMENTS
`
`58178456
`JP
`60189531
`JP
`2141056
`JP
`417160
`JP
`4192027
`JP
`5292176
`JP
`855022
`JP
`8263383
`JP
`9114745
`JP
`9134311
`JP
`9134330
`JP
`9198778
`JP
`wo
`9514265
`wo
`9628820
`* cited by examiner
`
`10/1983
`9/1985
`5/1990
`111992
`7/1992
`1111993
`2/1996
`10/1996
`5/1997
`5/1997
`5/1997
`7/1997
`5/1995
`9/1996
`
`Primary Examiner-Hosuk Song
`(74) Attorney, Agent, or Firm-Greer, Bums & Crain, Ltd.
`
`(57)
`
`ABSTRACT
`
`A data protection method is used for protecting data
`recorded on a removable storage medium, such as an optical
`magnetic disk. The method includes the steps of authorizing
`to read and access a part of a directory area on a storage
`medium without specifying a password given to the remov(cid:173)
`able storage medium. When accessing the removable stor(cid:173)
`age medium, a user is required to input a password, the
`inputted password is compared with a predetermined
`password, and if not coincident, access is inhibited, and
`further, if coincident, it is permitted to access only one part
`of an area of the removable storage medium.
`
`22 Claims, 13 Drawing Sheets
`
`1
`12
`---------------------~-------------
`
`10
`
`107
`
`------ -·-------- "19"----------------------------------
`
`NETAPP ET AL. EXHIBIT 1006
`Page 1 of 25
`
`

`
`""""' = """"'
`~ w =
`
`""""' N
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`-------------~--1~----------------------------------~
`
`.
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`.
`
`107
`
`I
`
`MOTOR I
`
`SPINDLE·
`
`_.......-106
`_,-105
`
`· VCM
`
`eject
`
`ACTUATOR -104
`ACTUATOR ~103
`
`TRACK
`
`FOCUS
`
`"(
`
`CONTROLLER
`
`MOTER
`
`18/
`
`POW AMP.
`AGC AMP. -·
`RAMP.
`
`'
`
`16
`
`......;..
`
`.
`
`102
`
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`
`H DETECTOR
`.....-1-1 DIODE
`LASER
`
`f.
`
`WAMP.
`\
`~ 15
`DSP
`
`100
`
`1--H SENSOR
`
`\
`
`MPU
`
`10
`
`1
`
`FIG. 1
`
`\
`
`12
`
`11
`
`D-RAM
`
`,. .,
`
`-
`
`ODC
`
`·'
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`I
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`I
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`
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`3
`
`KEY
`;
`
`NETAPP ET AL. EXHIBIT 1006
`Page 2 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
`
`Sheet 2 of 13
`
`US 7,124,301 B1
`
`FIG. 2
`
`FAT
`
`DIR
`
`DATA
`
`I
`~
`
`n
`~
`
`m
`
`NETAPP ET AL. EXHIBIT 1006
`Page 3 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
`
`Sheet 3 of 13
`
`US 7,124,301 B1
`
`FIG. 3
`
`Reading (accessing)
`request to a disk
`
`S1
`
`NO
`
`S2
`
`YES
`
`NO
`
`S5
`
`Access error is returned
`
`Reading from
`and writing to
`the disk
`
`S 7
`
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`Page 4 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 4 of 13
`
`US 7,124,301 B1
`
`FIG. 4
`
`Inserting a medium to storage device
`or supplying a power of the device
`
`S01
`
`Judging the medium type, self check S02
`of storage medium or the like
`
`Determining an access range
`according to .a table 1
`
`503
`
`~ ,
`
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`Page 5 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 5 of 13
`
`US 7,124,301 B1
`
`FIG. 5
`
`Inputting a password
`
`510
`
`Recording the inputted
`password
`
`s 1 1
`
`'~
`
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`Page 6 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 6 of 13
`
`US 7,124,301 B1
`
`FIG. 6
`
`Reading Access Request
`
`S20
`
`S21
`
`NO
`
`S23
`NO
`
`Reading out the
`data
`
`S22
`
`S24
`
`Reading out the data
`and the password is
`. employed for
`decoding
`
`Returning an error
`
`S .. 25 OK
`
`OK
`
`E r r or
`
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`Page 7 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 7 of 13
`
`US 7,124,301 B1
`
`FIG. 7
`
`Inputting a password
`
`S30
`
`S31
`
`NO
`
`YES
`
`Recording the inputted
`password
`
`S32
`
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`Page 8 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 8 of 13
`
`US 7,124,301 B1
`
`FIG. 8
`
`Reading access request
`
`540
`
`541
`
`NO
`
`Readjng out the requested
`sector
`
`S43
`
`YES
`
`Reading out the data S 4 2
`
`Reading out the data
`for decoding
`
`S 4 5
`
`Read OK
`
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`Page 9 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 9 of 13
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`US 7,124,301 B1
`
`FIG. 9
`
`Writi!"Q. access request
`
`S50
`
`NO
`
`S51
`NO
`
`53
`
`Encrypting and writing the
`data
`
`S 5 4 Writing . the data S 5 2
`
`E r r o r
`w r i t e
`
`Wr
`
`t e OK
`
`NETAPP ET AL. EXHIBIT 1006
`Page 10 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
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`Sheet 10 of 13
`
`US 7,124,301 B1
`
`FIG. 10
`
`Inputting .a password
`
`560
`
`NO
`
`YES
`
`YES
`
`565
`
`S62
`
`Inhibiting access to
`the medium
`
`Authorizing to read out
`the directory area
`
`Authorizing access to
`the whole storage
`
`NETAPP ET AL. EXHIBIT 1006
`Page 11 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
`
`Sheet 11 of 13
`
`US 7,124,301 B1
`
`FIG. 11
`
`WRPW is specified on a storage
`medium
`
`S 9 0
`
`NAC
`disabling all
`accesses
`
`S97
`
`Enabling to read
`BOA directory
`
`ROE
`Enabling to
`read out
`
`AWE
`Enabling to read
`and write
`
`892
`
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`

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`U.S. Patent
`
`Oct. 17, 2006
`
`Sheet 12 of 13
`
`US 7,124,301 B1
`
`FIG. 12
`
`WRPW is not set and RDPW
`is set ·
`
`S100
`
`YES
`
`NO
`
`NO
`5106
`
`5105
`
`5102
`
`NAC
`disabling all
`accesses
`
`Enabling to read a
`BOR directory
`
`R WE
`enabling to read and
`write
`
`NETAPP ET AL. EXHIBIT 1006
`Page 13 of 25
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`

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`U.S. Patent
`
`Oct. 17, 2006
`
`Sheet 13 of 13
`
`US 7,124,301 B1
`
`FIG. 13
`
`Both WRPW and RDPW are
`not set
`
`S110
`
`' I
`
`AWE
`Enabling to read and write
`
`s 1 1 1
`
`NETAPP ET AL. EXHIBIT 1006
`Page 14 of 25
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`

`
`US 7,124,301 B1
`
`1
`DATA PROTECTION METHOD FOR A
`REMOVABLE STORAGE MEDIUM AND A
`STORAGE DEVICE USING THE SAME
`
`BACKGROUND OF THE INVENTION
`
`2
`storage medium a specified document is stored, the user
`must access all storage mediums randomly to find out which
`storage medium stores the specified document.
`However, when a password is set to a storage medium,
`i.e., a disk, according to the above-described conventional
`methods, the user should input the password every time he
`accesses the disk. That brings complicated operation for the
`user. Therefore, there is a possibility that the user wants to
`avoid the troublesome and then sets only one password for
`10 almost all disks, without differing the password in each disk.
`Moreover, it should be considered that a situation where
`a user forgets which storage medium provided in a remov(cid:173)
`able storage device has stored a specified document may
`frequently occur. This is because such the information itself
`that a certain storage medium "01" stores a specified docu(cid:173)
`ment "A", such as a diary, should be concealed.
`To avoid the above-described situation or condition, the
`user may put the label title such as the "secret business
`documents" on a storage medium "01", for example. This
`20 gives to the others a chance to illegally access data, and then,
`the secret may leak out. With the same reason, it is not
`suitable administration to print out a list of contents in each
`disk. Therefore, disk administration may become to be
`dependent on user's memories or uses easy keywords.
`Further, in an other mode, there is a case where one user
`instructs the other person to find and take out a disk, on
`which business information is recorded due to urgent
`requirement on ordinary business. In this case, a password is
`not informed to the instructed person, and therefore, the
`person carmot know which disk he should take out.
`Actually, the user should inform the password to the
`instructed person, or the disk administration is operated
`without any password in consideration with such the con-
`35 dition. In the foregoing case, the number of persons having
`known the password of the removable storage medium will
`increase unintentionally, and therefore, it becomes a prob(cid:173)
`lem from the view of the security. On the contrary, in the
`later case, a security function can not be fundamentally
`40 employed.
`On the other hand, a library storage device has been
`employed for automatically administrating multiple storage
`mediums. It is now considered to treat a storage medium
`protected by a password in such the storage device. In this
`45 case, a label or a serial number is employed on an individual
`storage medium to specifY each of the multiple storage
`mediums, which the library storage device administrates.
`Therefore, it is necessary that the library storage device can
`read out the label on each storage device.
`However, if a password is specified to refer such the label
`or the substation, it is general that the same password is
`specified to all disks that the library device administrates. In
`such the mode, once a password is specified to one disk,
`access all storage mediums would be permitted. Viewing
`55 from the point of system security, this situation is not
`acceptable.
`As described above, situations where disks are frequently
`exchanged and are referred occurs in a removable storage
`device. Therefore, when employing either of the conven-
`60 tiona! methods, it is inclined to form a careless
`administration, such that only one password is specified for
`almost all storage mediums. More particularly, the problem
`occurs if either of the above-described conventional method
`is applied to multiple removable storage mediums. As a
`65 mass-storage medium has larger capacity, much information
`illegally referred will increase, and therefore, a serious
`problem will occur.
`
`25
`
`1. Field of the Invention
`The present invention relates to a method for concealing
`and protecting data by employing a password to read and
`overwrite the data recorded in a removable storage medium
`provided in a storage device, which is connected to an
`information processor, such as a computer, a word processor
`and an electronic book apparatus, under a control from the
`storage device or the information processor, and the present
`invention also relates to a storage device using the method. 15
`2. Description of the Related Art
`There is a case where information should not be accessed
`by other persons that an original holder or administrator,
`because such the information relates to a personal privacy or
`secret information on business recorded in a storage device
`connected to an information processor, such as a computer
`and a word processor.
`However, it is almost easy to access the storage device of
`the information processor so as to retrieve data and to copy
`bulk data. This brings problems such that important data can
`be easily accessed and modified.
`To avoid such problem, it has been proposed that a
`password is given to a storage device, and then, a user must
`input the password when accessing data on the storage 30
`device. Then, if the inputted password does not coincide
`with a correct password given to the storage device, the user
`carmot be authorized to access the storage device.
`Various kinds of such structures and methods have been
`proposed, for example, in Japanese laid open patent appli(cid:173)
`cations No. 58-178456 (first conventional method),
`60-189531 (second conventional method) and 4-192027
`(third conventional method).
`In the first conventional method, a basic structure is
`disclosed, in which a password is recorded in a magnetic
`disk to allow the access to the disk only when the password
`is coincident with an inputted password.
`In the second conventional method, the structure is
`intended to protect contents stored in, particularly, an exter(cid:173)
`nal storage medium having a large storage capacity.
`However, a password given in a storage medium is checked
`with a password that supplied from an upper level device,
`and if both the passwords coincide, a user can access the
`storage medium, similarly to the first conventional method.
`These conventional methods are applicable not only to a
`storage device, such as a fixed disk having a large storage
`capacity with a volume table of contents (VTOC), but also
`to various kinds of removable storage mediums, such as
`storage devices with volume administrative information and
`an optical magnetic disk.
`Further, it is assumed in the third conventional method
`that one removable storage medium can be accessed from
`multiple persons. When one removable storage medium is
`divided into a plurality of logical partitions, a password is
`specified in each of the logical partitions. Therefore, it is
`possible to provide an exclusive partition for each user by
`inputting a password.
`However, the following problems are brought in either of
`the above-described conventional methods.
`That is, supposing a user uses plural removable storage
`mediums and then the user forgets in which removable
`
`50
`
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`

`
`US 7,124,301 B1
`
`3
`SUMMARY OF THE INVENTION
`Accordingly, it is an object of the present invention to
`provide a method for concealing and protec~ing data in. a
`removable storage medium, such as an optical magnetic
`disk to overcome the above-described shortage in the con(cid:173)
`ventional methods, and a storage device using the same.
`To attain the above-described object, the present applicant
`had noticed the following point:
`In the conventional methods, accessing a whole storage 10
`medium is permitted even when accessing only one part of
`information, such as administration information, i.e., infor(cid:173)
`mation of a recorded file name. That causes the above(cid:173)
`described problem for concealing and protecting data.
`Further administration information on a storage medium 15
`is generally written on a specified location or comparatively
`collective area. Or, in many cases, the administration infor(cid:173)
`mation on the storage medium can be restricted in a com(cid:173)
`paratively small area.
`Therefore, the present invention has a feature for com- 20
`paring an inputted password with a predetermined password
`when accessing a removable storage medium, inhibiting
`access to a whole removable storage medium if both of the
`passwords are inconsistent, but permitting only to read and
`access only a part of the removable storage medium includ- 25
`ing an administration area by employing a certain means.
`In a mode of the present invention, a password for
`permitting read access to only a restricted area is provided
`separately from a password, which is required to access the
`whole removable storage medium.
`For instance, an optical magnetic disk, which is pre(cid:173)
`scribed in IS0-13963, is managed by dividing 10 areas
`called as bands 0 to 9. Two passwords are provided to the
`optical magnetic disk. When the first password coincides, a
`user is allowed to access all of the bands 0 to 9, and when 35
`the second password coincides, the user is allowed to access
`only the band 0, on which the administration information is
`recorded.
`As file system administration information is generally
`written on the band 0 in some file systems, the user cannot
`access the whole disk, but he can access only the file system
`administrative information as the result in this mode.
`Further, in another mode of the present invention, a
`password for controlling access to a removable storage
`medium is set in advance in an exclusive area, of the
`removable storage medium, which a file system does not
`administrate.
`When a password specified by a command sent from a
`computer coincides with a predetermined password for 50
`permitting a user to write and read, the user can write and
`read to the whole removable storage medium on forward.
`Additionally, when the password specified by a command
`coincides with a password for permitting the user to read a
`part of the removable storage medium, the user can read out 55
`data only within a permitted range.
`Furthermore, in one mode of the present invention, one
`part area of the removable storage medium is recorded with
`a plain text, so that more utility can be obtained in a data
`protection method for removable storage medium by which 60
`data is encrypted and stored in the removable storage
`medium, a password is verified, and the data encryption is
`decoded when the password is authentic.
`When the password is determined not authentic by the
`verification, it becomes possible to access and read only one 65
`area of the removable storage medium where the plain text
`is recorded.
`
`30
`
`40
`
`45
`
`4
`As another mode of the structure employing the data
`encryption, first and second passwords are employed. In
`other words, data is encrypted and recorded by the second
`password in one part area of the storage medium, and the
`data is encrypted and recorded by the first password in the
`other part area of the storage medium. Then, the second
`password is encrypted by the first password and the second
`password is recorded in a specific reserved area of the
`removable storage medium.
`The one part area of the removable storage medium is
`encrypted and decoded by the second password, and other
`areas are encrypted and decoded by the first password.
`Thereby, when the password specified before accessing
`the removable storage medium is authentic as a first
`password, it becomes possible to access the whole of the
`removable storage medium by decoding the second pass(cid:173)
`word by the first password. Further, if the password is not
`authentic as the first password, it becomes possible to read
`only the one part area of the removable storage medium by
`employing the password as the second password.
`In each of the above-described modes, one part of the
`removable storage medium to which read access is permitted
`includes a label given to the removable storage medium, or
`all of or a part of the directory area as administrative
`information.
`Additionally, to determine the label given to the above(cid:173)
`described removable storage medium or the part of the
`directory area, the present invention provides the following
`methods: a method for determining from a capacity of the
`removable storage medium and a logical format type
`considered, and a method for writing a range specification
`by the use of a start logical block address and an end logical
`block address in a specific reserved area of the removable
`storage medium in advance, or a method for identifying an
`administrative area including a label or directory by an
`interface section for identifying a logical format of the
`storage medium, such as a device driver.
`With the structure of the present invention, even if the
`password given to the storage medium is not specified, the
`user is permitted to access one part of the directory area on
`the storage medium for reading out data from the one part.
`Therefore, it becomes possible to know an outline of
`information recorded in the storage medium without com(cid:173)
`plicating password administration, or making a security
`hole, i.e., without giving a weak point and loophole on
`security function. Thereby, it becomes possible to avoid
`careless accessing to secret information.
`For example, it is possible to set a same password for
`reading out administrative information to all disks, i.e.,
`storage mediums and each different password to each disk
`for accessing data in actual. This realizes that a retrieve to
`know which disk stores the required file can be executed by
`exchanging disks actually.
`For example, when a user instructs to an other person to
`deliver a disk in which a file named as "aa" is stored, the
`contents of the file "aa" cannot be accessed, and therefore,
`the possibility of leaking secret information can be reduced.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of one embodiment of an
`information processor including an optical magnetic disk
`apparatus as one embodiment of a storage device according
`to the present invention.
`FIG. 2 is an explanatory diagram of a structural layout of
`an optical magnetic disk storage medium, illustrating only a
`data zone of the optical magnetic disk storage medium.
`
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`Page 16 of 25
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`

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`US 7,124,301 B1
`
`10
`
`5
`FIG. 3 shows an operational flow chart of a first embodi(cid:173)
`ment according to the present invention in an information
`processor including a storage device employing a removable
`storage medium, such as an optical magnetic disk.
`FIG. 4 shows a flow chart for setting an authorized access
`range corresponding to the table 1 when a storage medium
`is inserted or a power of a device is ON.
`FIG. 5 is a flow chart for explaining registration of a disk
`password in a first example for the second embodiment.
`FIG. 6 is an operational flow chart of the first example for
`the second embodiment.
`FIG. 7 is a flow chart for explaining registration of a disk
`password in a second example or the second embodiment.
`FIG. 8 is an operational flow chart when controlling to
`read in the second example for the second embodiment.
`FIG. 9 is an operational flow chart when controlling to
`write in the second example for the second embodiment.
`FIG. 10 is an operational flow chart for explaining a
`control when employing two passwords in the third embodi- 20
`ment.
`FIG. 11 is a first operational flow chart when at medium
`is inserted and a power is supplied corresponding to a table
`7 in the third embodiment.
`FIG. 12 is a second operational flow chart when a medium
`is inserted and a power is supplied corresponding to a table
`7 in the third embodiment.
`FIG. 13 is a third operational flow chart when a medium
`is inserted and a power is supplied corresponding to a table 30
`7 in the third embodiment.
`
`6
`motor 105 and a voice control motor 106 for driving a head,
`which are controlled by the power amplifier 18, and further,
`a spindle motor 107 controlled by the motor controller 19 for
`rotating disk.
`On the other hand, reading and writing data is controlled
`by a SCSI command sent from a computer 2 to the optical
`magnetic disk controller (ODC) 11 according to an opera(cid:173)
`tor's instruction inputted from a key board 3. A display
`device 4 for displaying writing or reading data is connected
`to the computer 2.
`Optical magnetic disk controller (ODC) 11 including a
`firmware formed by a flush ROM has a function for ana(cid:173)
`lyzing a SCSI command sent from computer 2. It further has
`a function for controlling the system controller 10 to write
`15 and read data according to the SCSI command operated
`along with the MPU 12.
`It is of course understood that the present invention is not
`restricted to a SCSI command group, but is applicable even
`to other command groups, such as ATA, ATAPI or SASI.
`In here, a mechanical layout of a removable storage
`medium including an optical magnetic disk will be now
`considered. FIG. 2 illustrates only a data zone of a remov(cid:173)
`able storage medium. In the forward and backward sections
`25 of the data zone shown in FIG. 2, there is a test zone, not
`shown in FIG. 2, and an area or a reserved area where a
`firmware in a storage device administrates the disk and
`which is not used as an area for writing user data, along the
`radius direction of the removable storage medium.
`The data zone of a removable storage medium shown in
`FIG. 2 includes a file allocation table (FAT) I for adminis(cid:173)
`trating an area in each cluster, which is a unit for writing
`data, a root directory II for showing a name or an attribute
`of a file or a directory, or a starting cluster number, and a data
`35 area III where contents of the file is recorded.
`It is possible to calculate an logical block address from a
`cluster number by simple arithmetic.
`FIG. 3 is an operational flow chart of the first embodiment
`according to the present invention in an information pro-
`40 cessor including storage device 1 of a removable storage
`medium, such as an optical magnetic disk. A user can access
`only directory information stored in the root directory II
`shown in FIG. 2 by specifYing one part including a volume
`label or directory information, i.e., an administration area of
`45 the removable storage medium, within a logical block
`address (LBA) as an authorized access range.
`As information of a file name, a directory to which a file
`is belonging and a start address is written in a root directory
`II, it is possible for user to easily find a location where a
`required file exists.
`At first, a reading request command is sent from the
`computer 2 to the optical magnetic disk controller (ODC) 11
`including a firmware of the storage device 1 employing a
`55 removable storage medium according to a SCSI command
`(STEP S1).
`Thereby, the optical magnetic disk controller (ODC)11
`judges whether or not an optical magnetic disk type storage
`medium of which writing/reading is controlled by the sys(cid:173)
`tem controller 10 is protected by a password (STEP S2). In
`here, the medium is not protected by a password, it is
`possible to read out from and write to a disk according to a
`read or write processing routine (STEP S7).
`On the other hand, when it is registered in optical mag-
`65 netic disk controller (ODC) 11 that the appropriate storage
`medium is protected by a password, i.e., a password is
`registered to the optical magnetic disk controller 11 in
`
`50
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`Throughout the following descriptions, the same refer(cid:173)
`ence numerals are used to denote and identifY corresponding
`or identical components.
`FIG. 1 is a block diagram of one embodiment of an
`information processor including an optical magnetic disk
`apparatus as one embodiment of a storage device applying
`the present invention. Although an magnetic disk apparatus
`will be explained as an embodiment, the present invention is
`not restricted to the optical magnetic disk apparatus. It
`should be of course understood that an magnetic disk
`apparatus or an optical disk apparatus for only reading out
`data is also applicable to the present invention.
`Returning to FIG. 1, an optical magnetic disk apparatus 1
`includes a system controller 10 for writing to and reading out
`from an optical magnetic disk used as a storage medium, and
`further, a control circuit section including an optical mag(cid:173)
`netic disk controller (ODC) 11 having a firmware where a
`software is stored to execute a method according to the
`present invention.
`A control circuit section includes a MPU 12 for control(cid:173)
`ling storage device 1 in total, a D-RAM 13 which is a buffer
`memory for reading or writing data, a DSP 14 for perform(cid:173)
`ing arithmetic conversion of reading and writing data, an
`amplifier 16 for reading data, an AGC amplifier 17, a power
`amplifier 18 for driving a head and a disk rotation motor 60
`controller 19.
`The system controller 10 includes a head sensor 100, a
`laser diode 101 for writing, driven by the amplifier 15, and
`a detector 102 for reading data, connected to the amplifier
`16.
`Additionally, the system controller 10 includes a focus
`actuator 103, a track actuator 104, a disk taking out (eject)
`
`NETAPP ET AL. EXHIBIT 1006
`Page 17 of 25
`
`

`
`US 7,124,301 B1
`
`8
`1 or supplying a power for an information processor (STEP
`SOl), a type of the inserted storage medium is checked, and
`settings are performed according to the type (STEP S02).
`Then, an authorized range for access is determined
`according to a relationship indicated in a table 1, which is an
`example table for determining the authorized range for
`reading access (when a sector length is 512 bytes)
`
`TABLE 1
`
`AUTHORIZED RANGE FOR ACCESS
`(LEAST UPPER BOUND OF LBA)
`
`cap
`spcx128 x2+32+32
`
`CAPACITY OF
`MEDTIJM (MB)
`
`Less than 12 8 MB
`Less than 25 6 MB
`Less than 512 MB
`More than 512
`
`spc
`
`4
`
`16
`32
`
`*cap means total capacity of a storage medium in a 1024 byte uuit
`*spc means a sector number in a cluster
`
`10
`
`15
`
`25
`
`20
`
`Actually, a logical format is estimated within a suitable
`range, and then, the LBA range for authorizing access is
`calculated according to the capacity of the storage medium.
`In this example, super floppy and hard disk format types are
`considered as a logical format type typically used in a
`personal computer. Then, it is assumed that FAT 16, i.e., a
`file allocation table for 16 bits, is employed in a segment
`format type, and the authorized range for access is set from
`LBA=O to a least upper bound ofLBA illustrated in the table
`1 according to the capacity of the storage medium.
`In other words, the authorized range for access can be
`specified by start and end logical block addresses.
`In the method for deciding the authorized range for access
`based on the capacity of the storage medium, when referring
`to examples of the formats written on disks by the super
`35 floppy format type and the hard disk format type,the LBA
`range for authorizing access does not always coincide with
`an area in which directory information is written by the both
`format types (refer to II of FIG. 2).
`
`7
`advance, the optical magnetic disk controller (ODC) 11
`judges whether or not the password specified by a user
`coincides with the registered password (STEP S3).
`In this example, the judgment whether or not a password
`coincides with the registered one is to determine authenticity
`of the password. Accordingly, the user can verify a password
`specified by the user by performing a certain operation to the
`specified password and recording the password performed
`with the certain operation in advance and comparing it with
`a password, which is specified by the computer 2 and
`performed with the certain operation in the same way,
`instead of comparing two passwords, directly.
`The password specified by the user is inputted from the
`keyboard 3 before an access request is sent from the com(cid:173)
`puter 2.
`In the above-described explanation, the optical magnetic
`disk controller (ODC) 11 includes a function for interfacing
`to the computer 2, and the computer 2 includes a function for
`interfacing to the optical magnetic disk controller (ODC) 11.
`Therefore, it is possible to configure so as to execute the
`judgment whether or not the password specified by the user
`coincides with the registered one in the interface section of
`the computer 2.
`Then, when the passwords coincide with each other, it
`becomes possible to execute processing for reading from or
`writing to a whole disk (STEP S7). If the both passwords do
`not coincide, it is judged whether or not the access request
`is for writing (STEP S4). If it is for writing, an error is
`notified to the computer 2 as an access error. The computer 30
`2, for example, displays an error message on the display
`device 4, to inform to the user according to an error
`processing (STEP SS).
`If not, in other word, the request is for reading, a specific
`area included in the above-described access request com(cid:173)
`mand sent from the computer 2 is checked. Then, it is
`checked whether or not the requested specific area is within
`an authorized range for reading access (STEP S6).
`If the requested specific area is not within the authorized
`range for reading access, an error is notified to the computer 40
`2, similarly to the writing access request (STEP SS). If the
`requested specific area is within the authorized range for
`reading access, the user can read data in read or write
`processing routine (STEP S7).
`In other word, it is possible only to read data within the
`authorized range for reading access, regardless of coinci(cid:173)
`dence or incoincidence of the both passwords in the embodi(cid:173)
`ment according to an operational flow chart shown in FIG.
`3.
`
`TABLE 2
`
`Start LBN
`
`SFPD
`
`HDD
`
`SE