A reconstruction theorem for abelian categories of twisted sheaves

We use an idea of Rosenberg to prove a reconstruction theorem for abelian categories of alpha-twisted quasi-coherent sheaves on quasi-compact and quasi-separated schemes X when alpha is in the Brauer group of X. By applying the work of To\"en on derived Azumaya algebras, we give a proof of C\u{a}ld\u{a}raru's conjecture.