CRYPTO 2012 Aug 19 – 23 Santa Barbara California USA Actively Secure Two-Party Evaluation of any Quantum Operation   Frédéric Dupuis (ETH Zürich) Louis Salvail (Université de Montréal, Canada) Jesper Buus Nielsen (Aarhus University)   Abstract: We provide the first two-party protocol allowing Alice and Bob to evaluate privately even against active adversaries a completely positive, trace-preserving map $F \in L(A_{in} \tensor B_{in}) \rightarrow L(A_{out} \tensor B_{out})$, given as a quantum circuit, upon their joint quantum input state $\rho_{in} \in D(A_{in} \tensor B_{in})$. Our protocol leaks no more to any active adversary than an ideal functionality for $F$ provided Alice and Bob have the cryptographic resources for active secure two-party classical computation. Our protocol is constructed from the protocol for the same task secure against specious adversaries presented by Dupuis, Nielsen and Salvail at Crypto 2010.