Method and system for variable password access

• US 5,682,475 A
• Filed: 12/30/1994
• Issued: 10/28/1997
• Est. Priority Date: 12/30/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Johnson, William J., Weber, Owen W.
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): LE, DIEU MINH T
• Application Number:
  US08/366,693
• Time in Patent Office: 1,033 Days
• Field of Search: 395/188.01, 395/186, 395/726, 395/725, 395/187.01, 380/4, 380/24, 380/25, 380/23, 364/222.5, 364/286.5, 364/261, 364/286.4, 364/260.81
• US Class Current: 726/18
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G07C 9/33 by means of a password

Abstract

A method and system are provided for controlling access to a data processing system through the use of a variable password. In one embodiment, the invention substitutes the value of a variable into an expression contained in a predefined password, evaluates the expression and password, and compares the result of the valuation of the password to a character string input to the data processing system, granting access if they are identical. A range of values of certain characters of the password may be permitted. The password may require that certain characters be entered within a defined time interval measured from the entry of other characters. The values of environment variables, which are referenced by the variable password, may change from time to time, as a function, for example, of the current time or temperature or system utilization.

Claims

1. A method, performed in a data processing system, for granting access to the data processing system, said data processing system including a predefined time interval, an environment variable, and a multiple character stored password, said stored password having specified first and second characters and a specification of a third character whose identity is dependent upon a value of the environment variable and an arithmetic operation to be performed upon the environment variable such that the identity of the third character is not equal to the value of the environment variable, wherein said third character may be one of said first and second characters, the method comprising the computer implemented steps of:

accepting an input of a multiple character keyed-in password, said keyed-in password including characters that correspond to the specified first and second characters of the stored password, said keyed-in password further including a character corresponding to the third character of the stored password;

determining whether the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable;

determining the length of time elapsed between the inputting of the corresponding first character of the keyed-in password and the inputting of the corresponding second character of the keyed-in password; and

granting access to the data processing system if the determined length of time elapsed is within the predefined time interval and if the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable.

2. The method of claim 1 wherein the predefined time interval includes a predefined range of time.

3. The method of claim 1 wherein the value of the environment variable includes a range of values and wherein the value of the character whose identity is dependent upon the value of the environment variable also includes a range of values.

4. A data processing system, comprising:

a predefined time interval;

an environment variable;

a multiple character stored password, said stored password having specified first and second characters and a specification of a third character whose identity is dependent upon a value of the environment variable and an arithmetic operation to be performed upon the environment variable such that the identity of the third character is not equal to the value of the environment variable, wherein said third character may be one of said first and second characters;

means for accepting an input of a multiple character keyed-in password, said keyed-in password including characters that correspond to the specified first and second characters of the stored password, said keyed-in password further including a character corresponding to the third character of the stored password;

means for determining whether the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable;

means for determining the length of time elapsed between the inputting of the corresponding first character of the keyed-in password and the inputting of the corresponding second character of the keyed-in password; and

means for granting access to the data processing system if the determined length of time elapsed is within the predefined time interval and if the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable.

5. The data processing system of claim 4 wherein the predefined time interval includes a predefined range of time.

6. The data processing system of claim 4 wherein the value of the environment variable includes a range of values and wherein the value of the character whose identity is dependent upon the value of the environment variable also includes a range of values.

7. A computer program product, for use in a data processing system, for granting access to the data processing system, said data processing system including a predefined time interval, an environment variable, and a multiple character stored password, said stored password having specified first and second characters and a specification of a third character whose identity is dependent upon a value of the environment variable and an arithmetic operation to be performed upon the environment variable such that the identity of the third character is not equal to the value of the environment variable, wherein said third character may be one of said first and second characters, the computer program product comprising:

a computer usable medium having computer readable program code embodied in said medium for granting access to the data processing system, said computer program product including;

computer readable program code means for accepting an input of a multiple character keyed-in password, said keyed-in password including characters that correspond to the specified first and second characters of the stored password, said keyed-in password further including a character corresponding to the third character of the stored password;

computer readable program code means for determining whether the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable;

computer readable program code means for determining the length of time elapsed between the inputting of the corresponding first character of the keyed-in password and the inputting of the corresponding second character of the keyed-in password; and

computer readable program code means for granting access to the data processing system if the determined length of time elapsed is within the predefined time interval and if the identity of the character corresponding to the third character of the stored password is equal to the result of performing the arithmetic operation on the environment variable.

8. The computer program product of claim 7 wherein the predefined time interval includes a predefined range of time.

9. The computer program product of claim 7 wherein the value of the environment variable includes a range of values and wherein the value of the character whose identity is dependent upon the value of the environment variable also includes a range of values.