System for detecting improper rewrites of data system for using separate reader writer passwords
First Claim
1. 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.
1 Assignment
0 Petitions
Accused Products
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.
60 Citations
26 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. 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. - View Dependent Claims (13, 14, 15, 16)
-
-
17. 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. - View Dependent Claims (18, 19, 20, 21)
-
-
22. 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. - View Dependent Claims (23, 24, 25, 26)
-
Specification