Method of assessing security of an information access system

[0001] The present invention relates, in general, to electronic computers and digital processing systems support and, in particular, to security levels.

[0002] Information access systems are not completely secure. They are susceptible to denial attacks and intrusion attacks. Being able to assess the security of an information access system is important when deciding which one to use.

[0003] Prior art methods of assessing security of information access systems include a method of receiving security information, categorizing it, scoring it, and determining the level of security. The result only produces a low, medium, or high assessment. Another method scans remote systems and surveys them for aspects that may have security vulnerabilities. The result is only a table for each remote system listing those aspects.

[0004] Assigning a real and objective measure of the security of an information access system is not addressed in the prior art. In the prior art, the resulting security assessment is subjectively qualified as low, medium or high. The prior art does not discuss the trade-offs of favoring one aspect the security over another. Other prior art simply scans remote computers and returns vulnerability aspects of the system. The result is just a table with the configuration of the system. Again, it produces no objective security measure. Therefore, there is a need for a method to objectively assess the security of an information access system. The present invention does just that.

[0005] U.S. Pat. Appl. No. 20060129810 A1, entitled “METHOD AND APPARATUS FOR EVALUATING SECURITY OF SUBSCRIBER NETWORK,” discloses a method of receiving information regarding a subscriber network. That information is then classified and given scores. Those scores result in the subscriber network being given security vulnerability levels of low, medium or high. U.S. Pat. Appl. No. 20060129810 A1 is hereby incorporated by reference into the specification of the present invention.

[0006] U.S. Pat. No. 7,328,454, entitled “SYSTEMS AND METHOD FOR ASSESSING COMPUTER SECURITY,” discloses a method for identifying the aspects of a system vulnerable to an attack. A system scans remote systems and checks for aspects known to be vulnerable to an attack. The result is simply a list of possible components where each remote system could be attacked. U.S. Pat. No. 7,328,454 is hereby incorporated by reference into the specification of the present invention.

[0007] It is an object of the present invention to assess the security of an information access system.

[0008] The present invention is a method of assessing security of an information access system.

[0009] The first step of the method is selecting at least one user-definable verification mechanism.

[0010] The second step of the method is estimating an error tradeoff plot for each user-definable verification mechanism showing false acceptance rate versus false rejection rate.

[0011] The third step of the method is selecting a false acceptance rate from each error tradeoff plot.

[0012] The fourth step of the method is determining a false rejection rate that corresponds to each of the selected false acceptance rates.

[0013] The fifth step of the method is combining the false acceptance rates to determine intrusion protection.

[0014] The sixth step of the method is combining the false rejection rates to determine denial protection.

[0015] The seventh step of the method is combining the intrusion protection and denial protection as the assessment of the information access system.

[0017] The present invention is a method of assessing security of an information access system.

[0018] FIG. 1 is a flow chart of the present invention.

[0019] The first step 1 of the method is selecting at least one user-definable verification mechanism. In the preferred embodiment, the verification mechanisms are selected from username, password, personal identification number, and at least one biometric, e.g., fingerprint, retinal scan, voice, face, etc.

[0020] The second step 2 of the method is estimating an error tradeoff plot for each verification mechanism. Each error tradeoff plot plots the false acceptance rate versus the false rejection rate. In the preferred embodiment, each error tradeoff plot is derived empirically.

[0021] The third step 3 of the method is selecting a false acceptance rate from each error tradeoff plot.

[0022] The fourth step 4 of the method is determining a corresponding false rejection rate for each selected false acceptance rate.

[0023] The fifth step 5 of the method is combining the determined false acceptance rates to find intrusion protection (IP). In the preferred embodiment, the false acceptance rates are combined by calculating

[0024] $\mathrm{IP}=-10\sum _{i=1}^n\left({\log }_{10}\left(\mathrm{false}\mathrm{acceptance}{\mathrm{rate}}_i\right)\right).$

[0025] The sixth step 6 of the method is combining the false rejection rates to determine denial protection (DP). In the preferred embodiment, the false rejection rates are combined by calculating

[0026] $\mathrm{DP}=-10{\log }_{10}\left(\sum _{i=1}^n\left(\mathrm{false}\mathrm{rejection}{\mathrm{rate}}_i\right)\right).$

[0027] The seventh step 7 of the method is combining the IP and DP as the assessment of the information access system. In the preferred embodiment, the IP and DP are combined by calculating √{square root over ((IP)²+(DP)²)}{square root over ((IP)²+(DP)²)} and

[0028] $\frac{{180}^{°}}{\pi }\mathrm{arc}\tan \left(\frac{\mathrm{DP}}{\mathrm{IP}}\right).$
The first result determines the security magnitude so that the larger the result, the better the security of the information access system. The second result determines the security direction. At 45°, the denial protection is balanced with the intrusion protection. Below 45°, intrusion protection is favored, and above 45°, denial protection is favored.