Security in Computing, Third Edition

6.6. Multilevel Databases

So far, we have considered data in only two categories: either sensitive or nonsensitive. We have alluded to some data items being more sensitive than others, but we have allowed only yes-or-no access. Our presentation may have implied that sensitivity was a function of the attribute, the column in which the data appeared, although nothing we have done depended on this interpretation of sensitivity. Such a model appears in Table 6-15, where two columns are identified (by shading) as sensitive. In fact, though, sensitivity is determined not just by attribute but also in ways that we investigate in the next section.

The Case for Differentiated Security

Consider a database containing data on U.S. government expenditures. ...