<p>An authentication apparatus to authenticate a user requesting access to a restricted resource in a computer system comprising: an interface adapted to receive an indication of a user request to access the restricted resource, the request having associated a current user context defining one or more characteristics of the user; a receiver adapted to receive a user selected authentication scheme from a set of authentication schemes for the current user context; a comparator adapted to compare the user selected authentication scheme with a set of user-specific rules, each rule indicating one or more authentication schemes for a user context as preferred authentication schemes; an access controller adapted to permit access to the restricted resource based on the comparison so as to prevent access to the restricted resource when the rules indicate one or more authentication schemes other than the user selected authentication scheme are preferred for the current user context.</p>
