Authentication of users, for example, must not depend on simple combinations of user ID and password. Users choose obvious passwords and are careless in keeping them to themselves. More reliable two-factor authentication requires any two of something one knows (such as a password), something one has (such as an active encryption token) and something one is (such as a fingerprint). Judicious use of two-factor schemesfor example, in granting physical access to facilitiesimproves security of everything within that two-factor perimeter. Databases should incorporate security in their own structure, rather than assume that application developers will serve as data guardians. Individual database user accounts are more difficult to administer than group IDs, but nothing else provides sufficient accountability for data alterations. Users may, however, share common roles that give them role-based privileges such as adding records only to specified tables.For any given enterprise, or for any single user, its not necessary (or even possible) to be immune to all attacks; its enough to be among the least-vulnerable targets. In a world of passwords that readily yield to a trivial dictionary search, for example, a system whose passwords combine two unrelated wordsespecially with a punctuation character in betweenwill almost certainly not be the first one cracked.Its a target-rich environment. For all but the best-known, high-value targets, merely being in the least-vulnerable third of the population for every common mode of attack will translate into high returns on security investments. Technology Editor Peter Coffee can be reached at email@example.com.