In this work, we continue the study of the MIQ model and prove severe lower bounds on the number of ideal queries per session. Following are our main results:
1) There exists a two-party functionality that cannot be securely realized in the MIQ model with only a constant number of ideal queries per session. 2) There exists a two-party functionality that cannot be securely realized in the MIQ model by any constant round protocol, with any polynomial number of ideal queries per session.
Both of these results are unconditional and even rule out protocols proven secure using a non-black-box simulator. We in fact prove a more general theorem which allows for trade-off between round complexity and the number of ideal queries per session. We obtain our negative results in the following two steps:
1) We first prove our results with respect to black-box simulation, i.e., we only rule out simulators that make black-box use of the adversary. 2) Next, we give a technique to compile our negative results w.r.t. black-box simulation into full impossibility results (ruling out non-black-box simulation as well) in the MIQ model. Interestingly, our compiler uses ideas from the work on obfuscation using tamper-proof hardware, even though our setting does not involve any hardware tokens.Category / Keywords: foundations / secure computation, concurrent security Original Publication (with minor differences): IACR-EUROCRYPT-2013 Date: received 7 May 2015 Contact author: abhishek at cs jhu edu Available format(s): PDF | BibTeX Citation Note: Full version of the Eurocrpt 2013 paper. Version: 20150508:112127 (All versions of this report) Short URL: ia.cr/2015/439 Discussion forum: Show discussion | Start new discussion