Distinguished Professor Eric Allender's research involves trying to show that some tasks are essentially impossible to compute. For example, we know that there are some transformations on moderately-small inputs (say, a few hundred bits in length) that cannot be computed by any circuit that will fit in the galaxy; such functions are certainly ``hard'' to compute. The field of computational complexity theory tries to give us more examples of ``hard'' functions. This is important, since secure on-line commerce relies on unproven assumptions about functions that are ``hard'' in this sense. Allender is a former chair of the computer science department, was a Fulbright Fellow in South Africa, and is a Fellow of the ACM. When he's not proving theorems, he and his wife love to dance.