Identity management systems (IDMS) allow government agencies to meet security mandates such as those established by Homeland Security Presidential Directive-12. This directive requires federal agencies to adopt standard methods for securing physical access to buildings and logical access to information systems. While they are not subject to the directive, many state and local governments are moving toward compliance as well. These agencies cite a desire to tighten their security as the chief reason for implementing IDMS. These solutions can also reduce the number of passwords that employees are required to remember, which, in turn, lowers the risks associated with using unsecured passwords or writing them down. Some types of public sector agencies require the capability to manage large numbers of roles in addition to employees. In its most basic form, an IDMS authenticates users, manages access to resources, and lets agencies obtain better control over password security. One of the biggest challenges in implementing IDMS is not technological, but practical. Identity management is actually driven by business practices, according to industry experts, and since IDMS impacts every major system in an organization, it is important that managers identify each process involved. When looking for an IDMS, agencies should consider issues such as the server operating systems it supports, whether they can set policies for password difficulty and expiration, if it supports central caching of keys, and whether it logs failed log-ins, among others.