Patent · US Expired

Secure access to software modules

US6000032A · kind A · utility

20Cited by
5References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 15, 1997
Grant dateDec 7, 1999
Priority date
Expiry dateJul 15, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2221/2103
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Apparatus and method for obtaining a security value (50) that enables a calling module (7) to achieve secure access to a called module (5) within a digital computer (1). A distributive invertible function f is selected. f may be the cyclic redundancy check function modulo p, where p is a prime number. A desired residual value r associated with the application of f and a desired size of the security value (50) are also selected. Space is allocated within the called module (5) for storing the security value (50). A portion of the called module (5) is designated as a test block (51). f is applied to a numerical representation of test block (51) to generate a first challenge value CV1. f is applied to a numerical value of the security value (50) and a number representative of the location of the security value (50) within the called module (5) to calculate a second challenge value CV2. n is the number of bits from the beginning of the security value (50) to the end of the called module (5). CV1 and CV2 are typically calculated by called module (5). Calling module (7) then calculates the security value (50) based upon CV1 and CV2, and using f. Called module (5) uses this calculated valu…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.