The United States banking industry has been directed by its regulatory agencies to provide authentication stronger than single factor for “high risk” transactions, as a defense against phishing. Financial institutions have a wide array of options available to them to meet this requirement, and choosing among those options is likely not a simple matter. Factors involved in the decision process i...

For a multidimensional control problem (P)K involving controls u ∈ L∞, we construct a dual problem (D)K in which the variables ν to be paired with u are taken from the measure space rca (Ω, B) instead of (L∞)∗. For this purpose, we add to (P)K a Baire class restriction for the representatives of the controls u. As main results, we prove a strong duality theorem and saddle-point conditions.