US5455941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for detecting improper rewrites of data system for using separate reader writer passwords
Assignee: Canon Inc
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Filing: 1992-02-27
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Granted: 1995-10-03
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Expires: 2012-02-27
Abstract
Abstract In storing data in one file, consisting of a plurality of blocks of data, a first code is generated by converting a password and a predetermined portion of each of the blocks of data. This portion may be, for example, the data block itself or identification information such as a name. The code is stored in correspondence to the stored data. In reading the stored data, a second code is generated by performing the same conversion on the password and the predetermined portion of the stored data. A comparison is made between the generated second code and the first code stored. Failure of the two to match indicates that an improper rewrite has occurred. In such a case, that occurrence may simply be noted, access to the data may be prohibited; more generally, what processing is performed, or is permitted, is varied according to the result of the comparison.
Inventors
- 👤 Yasuhiro Okuno
- 👤 Tadashi Yamakawa
- 👤 Masaaki Nagashima
- 👤 Takayuki Sasaki
- 👤 Takahiro Kurosawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:37
CPC Classifications
G; G06; G06F; G06F21/00; G06F21/60; G06F21/62; G06F21/6209; G06F12/00; G06F12/14; G06F12/1458; G06F12/1466; G06F21/64; G06Q; G06Q10/00; G06Q10/10
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
168 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data has been made for each block of data other than by the writer of that block of data, comprising the steps of: (A) in storing the data: designating a block of data; inputting a password; generating a first code by converting a combination of the input password and the designated block of data in a pre-determined procedure; and storing said first code in correspondence to the designated block of data; (B) in reading the stored data: designating the block of data; inputting the password; generating a second code by converting a combination of the input password and the designated block of data in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and determining that an improper rewrite of said designated block of data has been made, if the comparison result is unequal.
Claim 2
Independent Claim
168 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data has been made for each block of data other than by the writer of that block of data, comprising the steps of: (A) in storing the data: designating a block of data; inputting a password; generating a first code by converting a combination of the input password and the designated block of data in a pre-determined procedure; and storing said first code in correspondence to the designated block of data; (B) in reading the stored data: designating the block of data; inputting the password; generating a second code by converting a combination of the input password and the designated block of data in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and determining that an improper rewrite of said designated block of data has been made, if the comparison result is unequal.
Claim 3
Dependent Claim
12 words
The method according to claim 1, wherein said data comprises a text.
Claim 4
Dependent Claim
12 words
The method according to claim 1, wherein said data comprises a program.
Claim 5
Dependent Claim
16 words
The method according to claim 1, wherein the block of data is separated by punctuation information.
Claim 6
Dependent Claim
29 words
The method according to claim 1, wherein said first code is stored in the same file as a blocked data corresponding to said code so as to be distinguishable.
Claim 7
Dependent Claim
40 words
The method according to claim 4, wherein the punctuation information belongs to each block of data, and said first code is stored by being included in the punctuation information belonging to a block of data corresponding to said first code.
Claim 8
Dependent Claim
29 words
The method according to claim 4, wherein said punctuation information includes attribute information of each block of data to be converted upon generation of said first and second codes.
Claim 9
Dependent Claim
31 words
The method according to claim 1, wherein the designation of said block of data is made by designating positional information of said block of data in the whole body of data.
Claim 10
Dependent Claim
33 words
The method according to claim 1, wherein each block of data is given a name, and the designation of the block of data is made using the name of the block of data.
Claim 11
Dependent Claim
36 words
The method according to claim 9, wherein said first code is stored in a file having a file name which is a name of a block of data corresponding to said code followed by an expander.
Claim 12
Dependent Claim
30 words
The method according to claim 9, wherein said block of data is separated by punctuation information, and the name of said block of data is included in the punctuation information.
Claim 13
Independent Claim
190 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data, written by a plurality of persons, has been made for each block of data, by a person other than the writer of the block of data, and performing a processing in accordance with a result of that determination, comprising the steps of: (A) in storing each block of data; inputting a password for each block of data; generating first codes by converting combination of each input password and each block of data in a predetermined procedure; and storing the first codes in correspondence to the block of data; (B) in processing the stored data; inputting the password for each designated block; generating a second code by converting a combination of the designated block of data and the input password therefor in said predetermined procedure; comparing the generated second code and one of the first codes stored in correspondence to the designated block of data; and including the designated block of data in a subject of processing if and only if a result of the comparison is equal.
Claim 14
Independent Claim
190 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data, written by a plurality of persons, has been made for each block of data, by a person other than the writer of the block of data, and performing a processing in accordance with a result of that determination, comprising the steps of: (A) in storing each block of data; inputting a password for each block of data; generating first codes by converting combination of each input password and each block of data in a predetermined procedure; and storing the first codes in correspondence to the block of data; (B) in processing the stored data; inputting the password for each designated block; generating a second code by converting a combination of the designated block of data and the input password therefor in said predetermined procedure; comparing the generated second code and one of the first codes stored in correspondence to the designated block of data; and including the designated block of data in a subject of processing if and only if a result of the comparison is equal.
Claim 15
Dependent Claim
15 words
The method according to claim 12, wherein the password comprises information corresponding to the user.
Claim 16
Dependent Claim
12 words
The method according to claim 12, wherein the data comprises a text.
Claim 17
Dependent Claim
12 words
The method according to claim 12, wherein the data comprises a program.
Claim 18
Dependent Claim
39 words
The method according to claim 12, further comprising the step of executing a second process different from a process to be executed when the comparison result is equal for a block of data for which the comparison is unequal.
Claim 19
Independent Claim
176 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data written by a plurality of persons has been made for each block of data by a person except for the writer thereof, comprising the steps of: (A) in storing the data: designating a block of data; inputting and registering a password for the designated block; generating a first code by converting a combination of the input password and the designated block of data in a predetermined procedure; and storing said first code in correspondence to the designated block of data; (B) in reading the stored data: designating the block of data; generating a second code by converting a combination of the designated block of data and the password registered therefor in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and determining that the improper rewrite of said designated block of data has been made if the comparison result is equal.
Claim 20
Independent Claim
176 words
A method for determining whether or not an improper rewrite of stored data in a file comprising a plurality of blocks of data written by a plurality of persons has been made for each block of data by a person except for the writer thereof, comprising the steps of: (A) in storing the data: designating a block of data; inputting and registering a password for the designated block; generating a first code by converting a combination of the input password and the designated block of data in a predetermined procedure; and storing said first code in correspondence to the designated block of data; (B) in reading the stored data: designating the block of data; generating a second code by converting a combination of the designated block of data and the password registered therefor in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and determining that the improper rewrite of said designated block of data has been made if the comparison result is equal.
Claim 21
Dependent Claim
12 words
The method according to claim 17, wherein the data comprises a text.
Claim 22
Dependent Claim
12 words
The method according to claim 17, wherein the data comprises a program.
Claim 23
Dependent Claim
18 words
The method according to claim 17, wherein the password is registered in correspondence to each block of data.
Claim 24
Dependent Claim
16 words
The method according to claim 17, wherein the passwords are registered in correspondence to each other.
Claim 25
Independent Claim
184 words
A method for preventing an improper rewrite of stored data in a file comprising a file name and a plurality of blocks of data written by a plurality of persons has been made for each block of data by a person except for the writer thereof, comprising the steps of: (A) in storing each block of data: inputting a password for each block of data; generating first codes by converting combinations of each input password and a corresponding block of data in a predetermined procedure, respectively; and storing said first codes in correspondence to their respective blocks of data; (B) in rewriting a block of data in the file: reading out the file with a file name; designating the block of data; inputting the password for the designated block; generating a second code by converting a combination of the designated block of data and the input password therefor in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and prohibiting a rewrite of the designated block if the comparison result if unequal.
Claim 26
Independent Claim
184 words
A method for preventing an improper rewrite of stored data in a file comprising a file name and a plurality of blocks of data written by a plurality of persons has been made for each block of data by a person except for the writer thereof, comprising the steps of: (A) in storing each block of data: inputting a password for each block of data; generating first codes by converting combinations of each input password and a corresponding block of data in a predetermined procedure, respectively; and storing said first codes in correspondence to their respective blocks of data; (B) in rewriting a block of data in the file: reading out the file with a file name; designating the block of data; inputting the password for the designated block; generating a second code by converting a combination of the designated block of data and the input password therefor in said predetermined procedure; comparing the generated second code and the first code stored in correspondence to said designated block of data; and prohibiting a rewrite of the designated block if the comparison result if unequal.
Claim 27
Dependent Claim
12 words
The method according to claim 22, wherein the data comprises a text.
Claim 28
Dependent Claim
11 words
The method according to claim 22, wherein the data comprises program.
Claim 29
Dependent Claim
18 words
The method according to claim 22, wherein the identification information comprises positional information of each block of data.
Claim 30
Dependent Claim
18 words
The method according to claim 22, wherein the identification information comprises a name of each block of data.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |