DOCSLIB.ORG

Secure Outsourced Garbled Circuit Evaluation for Mobile Devices

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Secure Outsourced Garbled Circuit Evaluation for Mobile Devices Secure Outsourced Garbled Circuit Evaluation for Mobile Devices Henry Carter, Georgia Institute of Technology; Benjamin Mood, University of Oregon; Patrick Traynor, Georgia Institute of Technology; Kevin Butler, University of Oregon This paper is included in the Proceedings of the 22nd USENIX Security Symposium. August 14–16, 2013 • Washington, D.C., USA ISBN 978-1-931971-03-4 Open access to the Proceedings of the 22nd USENIX Security Symposium is sponsored by USENIX Secure Outsourced Garbled Circuit Evaluation for Mobile Devices Henry Carter Benjamin Mood Georgia Institute of Technology University of Oregon [email protected] [email protected] Patrick Traynor Kevin Butler Georgia Institute of Technology University of Oregon [email protected] [email protected] Abstract ity even after the discovery of Yao’s garbled circuit [43], recent advances in this space have made such computa- Garbled circuits provide a powerful tool for jointly tion increasingly practical. Today, functions as complex evaluating functions while preserving the privacy of each as AES-128 and approaching one billion gates in size are user’s inputs. While recent research has made the use possible at reasonable throughputs, even in the presence of this primitive more practical, such solutions generally of a malicious adversary. assume that participants are symmetrically provisioned While recent research has made the constructions in with massive computing resources. In reality, most peo- this space appreciably more performant, the majority of ple on the planet only have access to the comparatively related work makes a crucial assumption - that both par- sparse computational resources associated with their mo- ties are symmetrically provisioned with massive comput- bile phones, and those willing and able to pay for ac- ing resources. For instance, Kreuter et al. [25] rely on the cess to public cloud computing infrastructure cannot be Ranger cluster at the Texas Advanced Computing Center assured that their data will remain unexposed. We ad- to compute their results using 512 cores. In reality, the dress this problem by creating a new SFE protocol that extent of a user’s computing power may be their mobile allows mobile devices to securely outsource the major- phone, which has many orders of magnitude less compu- ity of computation required to evaluate a garbled circuit. tational ability. Moreover, even with access to a public Our protocol, which builds on the most efficient gar- compute cloud such as Amazon EC2 or Windows Azure, bled circuit evaluation techniques, includes a new out- the sensitive nature of the user’s data and the history of sourced oblivious transfer primitive that requires signifi- data leakage from cloud services [40, 42] prevent the di- cantly less bandwidth and computation than standard OT rect porting of known SFE techniques. primitives and outsourced input validation techniques that force the cloud to prove that it is executing all pro- In this paper, we develop mechanisms for the secure tocols correctly. After showing that our extensions are outsourcing of SFE computation from constrained de- secure in the malicious model, we conduct an extensive vices to more capable infrastructure. Our protocol main- performance evaluation for a number of standard SFE tains the privacy of both participant’s inputs and outputs test applications as well as a privacy-preserving naviga- while significantly reducing the computation and net- tion application designed specifically for the mobile use- work overhead required by the mobile device for garbled case. Our system reduces execution time by 98.92% and circuit evaluation. We develop a number of extensions bandwidth by 99.95% for the edit distance problem of to allow the mobile device to check for malicious behav- size 128 compared to non-outsourced evaluation. These ior from the circuit generator or the cloud and a novel results show that even the least capable devices are ca- Outsourced Oblivious Transfer for sending garbled input pable of evaluating some of the largest garbled circuits data to the cloud. We then implement the new proto- generated for any platform. col on a commodity mobile device and reasonably provi- sioned servers and demonstrate significant performance 1 Introduction improvements over evaluating garbled circuits directly on the mobile device. Secure Function Evaluation (SFE) allows two parties to We make the following contributions: compute the result of a function without either side hav- Outsourced oblivious transfer & outsourced con- • ing to expose their potentially sensitive inputs to the sistency checks: Instead of blindly trusting the other. While considered a generally theoretical curios- cloud with sensitive inputs, we develop a highly 1 USENIX Association 22nd USENIX Security Symposium 289 efficient Outsourced Oblivious Transfer primitive how this paper differs from Salus; Section 3 provides that allows mobile devices to securely delegate the cryptographic assumptions and definitions; Section 4 for- majority of computation associated with oblivious mally describes our protocols; Section 5 provides secu- transfers. We also provide mechanisms to outsource rity discussion - we direct readers to our technical re- consistency checks to prevent a malicious circuit port [6] for full security proofs; Section 6 shows the re- generator from providing corrupt garbled values. sults of our extensive performance analysis; Section 7 These checks are designed in such a way that the presents our privacy preserving navigation application computational load is almost exclusively on the for mobile phones; and Section 8 provides concluding cloud, but cannot be forged by a malicious or “lazy” remarks. cloud. We demonstrate that both of our additions are secure in the malicious model as defined by Ka- 2 Related Work mara et al. [21]. Performance Analysis: Extending upon the imple- • Beginning with Fairplay [32], several secure two-party mentation by Kreuter et al. [25], we conduct an ex- computation implementations and applications have tensive performance analysis against a number of been developed using Yao garbled circuits [43] in the simple applications (e.g., edit distance) and crypto- semi-honest adversarial model [3, 15, 17, 19, 26, 28, 31, graphic benchmarks (e.g., AES-128). Our results 38]. However, a malicious party using corrupted in- show that outsourcing SFE provides improvements puts or circuits can learn more information about the to both execution time and bandwidth overhead. For other party’s inputs in these constructions [23]. To re- the edit distance problem of size 128, we reduce ex- solve these issues, new protocols have been developed to ecution time by 98.92% and bandwidth by 99.95% achieve security in the malicious model, using cut-and- compared to direct execution without outsourcing choose constructions [30], input commitments [41], and on the mobile device. other various techniques [22,34]. To improve the perfor- Privacy Preserving Navigation App: To demon- • mance of these schemes in both the malicious and semi- strate the practical need for our techniques, we de- honest adversarial models, a number of circuit optimiza- sign and implement an outsourced version of Dijk- tion techniques have also been developed to reduce the stra’s shortest path algorithm as part of a Naviga- cost of generating and evaluating circuits [8, 11, 24, 35]. tion mobile app. Our app provides directions for Kreuter et al. [25] combined several of these techniques a Presidential motorcade without exposing its loca- into a general garbled circuit protocol that is secure in tion, destination, or known hazards that should be the malicious model and can efficiently evaluate circuits avoided (but remain secret should the mobile device on the order of billions of gates using parallelized server- be compromised). The optimized circuits generated class machines. This SFE protocol is currently the most for this app represent the largest circuits evaluated efficient implementation that is fully secure in the mali- to date. Without our outsourcing techniques, such cious model. (The dual execution construction by Huang an application is far too processor, memory and et al. leaks one bit of input [16].) bandwidth intensive for any mobile phone. Garbled circuit protocols rely on oblivious transfer While this work is similar in function and provides schemes to exchange certain private values. While sev- equivalent security guarantees to the Salus protocols re- eral OT schemes of various efficiencies have been de- cently developed by Kamara et al. [21], our approach veloped [1, 30, 36, 39], Ishai et al. demonstrated that any is dramatically different. The Salus protocol frame- of these schemes can be extended to reduce kc oblivi- work builds their scheme on a completely different as- ous transfers to k oblivious transfers for any given con- sumption, specifically, that they are outsourcing work stant c [18]. Using this extension, exchanging potentially from low-computation devices with high communication large inputs to garbled circuits became much less costly bandwidth. With provider-imposed bandwidth caps and in terms of cryptographic operations and network over- relatively slow and unreliable cellular data connections, head. Even with this drastic improvement in efficiency, this is not a realistic assumption when developing solu- oblivious transfers still tend to be a costly step in evalu- tions in the mobile environment. Moreover, rather than ating garbled circuits. providing a proof-of-concept work
Load more

Recommended publications
  • Reusable Garbled Gates for New Fully Homomorphic Encryption Service Xu an Wang* Fatos Xhafa Jianfeng Ma Yunfei Cao and Dianhua T
    Int. J. Web and Grid Services, Vol. X, No. Y, XXXX Reusable garbled gates for new fully homomorphic encryption service Xu An Wang* School of Telecommunications Engineering, Xidian University, Xi’an, China and Key Laboratory of Information and Network Security, Engineering University of Chinese Armed Police Force, Xi’an, China Email: [email protected] *Corresponding author Fatos Xhafa Department of Computer Science, Technical University of Catalonia, Barcelona, Spain Email: [email protected] Jianfeng Ma School of Cyber Engineering, Xidian University, Shaanxi, China Email: [email protected] Yunfei Cao and Dianhua Tang Science and Technology on Communication Security Laboratory, Chengdu, China Email: [email protected] Email: [email protected] Abstract: In this paper, we propose a novel way to provide a fully homomorphic encryption service, namely by using garbled circuits. From a high level perspective, Garbled circuits and fully homomorphic encryption, both aim at implementing complex computation on ciphertexts. We define a new cryptographic primitive named reusable garbled gate, which comes from the area of garbled circuits, then based on this new primitive we show that it is very easy to construct a fully homomorphic encryption. However, the instantiation of reusable garbled gates is rather difficult, in fact, we can only instantiate this new primitive based on indistinguishable obfuscation. Furthermore, reusable garbled gates can be a core component for constructing the reusable garbled circuits, which can reduce the communication complexity Copyright © 200X Inderscience Enterprises Ltd. X.A. Wang et al. of them from O(n) to O(1). We believe that reusable garbled gates promise a new way to provide fully homomorphic encryption and reusable garbled circuits service fast.
    [Show full text]
  • Reusable Garbled Circuit Implementation of AES to Avoid Power Analysis Attacks Venkata Lakshmi Sudheera Bommakanti Clemson University
    Clemson University TigerPrints All Theses Theses 8-2017 Reusable Garbled Circuit Implementation of AES to Avoid Power Analysis Attacks Venkata Lakshmi Sudheera Bommakanti Clemson University Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Recommended Citation Bommakanti, Venkata Lakshmi Sudheera, "Reusable Garbled Circuit Implementation of AES to Avoid Power Analysis Attacks" (2017). All Theses. 2751. https://tigerprints.clemson.edu/all_theses/2751 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. Reusable Garbled Circuit Implementation of AES to Avoid Power Analysis Attacks A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Electrical Engineering by Venkata Lakshmi Sudheera Bommakanti August 2017 Accepted by: Dr. Richard Brooks, Committee Chair Dr. Richard Groff Dr. Rajendra Singh Abstract Unintended side-channel leaks can be exploited by attackers and achieved quickly, and using relatively inexpensive equipment. Cloud providers aren’t equipped to provide assurances of security against such attacks. One most well- known and effective of the side-channel attack is on information leaked through power consumption. Differential Power Analysis (DPA) can extract a secret key by measuring the power used while a device is executing the any algorithm. This research explores the susceptibility of current implementations of Circuit Garbling to power analysis attacks and a simple variant to obfuscate functionality and randomize the power consumption reusing the garbling keys and the garbled gates.
    [Show full text]
  • Privacy Preserving Computations Accelerated Using FPGA Overlays
    Privacy Preserving Computations Accelerated using FPGA Overlays A Dissertation Presented by Xin Fang to The Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Engineering Northeastern University Boston, Massachusetts August 2017 To my family. i Contents List of Figures v List of Tables vi Acknowledgments vii Abstract of the Dissertation ix 1 Introduction 1 1.1 Garbled Circuits . 1 1.1.1 An Example: Computing Average Blood Pressure . 2 1.2 Heterogeneous Reconfigurable Computing . 3 1.3 Contributions . 3 1.4 Remainder of the Dissertation . 5 2 Background 6 2.1 Garbled Circuits . 6 2.1.1 Garbled Circuits Overview . 7 2.1.2 Garbling Phase . 8 2.1.3 Evaluation Phase . 10 2.1.4 Optimization . 11 2.2 SHA-1 Algorithm . 12 2.3 Field-Programmable Gate Array . 13 2.3.1 FPGA Architecture . 13 2.3.2 FPGA Overlays . 14 2.3.3 Heterogeneous Computing Platform using FPGAs . 16 2.3.4 ProceV Board . 17 2.4 Related Work . 17 2.4.1 Garbled Circuit Algorithm Research . 17 2.4.2 Garbled Circuit Implementation . 19 2.4.3 Garbled Circuit Acceleration . 20 ii 3 System Design Methodology 23 3.1 Garbled Circuit Generation System . 24 3.2 Software Structure . 26 3.2.1 Problem Generation . 26 3.2.2 Layer Extractor . 30 3.2.3 Problem Parser . 31 3.2.4 Host Code Generation . 32 3.3 Simulation of Garbled Circuit Generation . 33 3.3.1 FPGA Overlay Architecture . 33 3.3.2 Garbled Circuit AND Overlay Cell .
    [Show full text]
  • Improved Garbled Circuit: Free XOR Gates and Applications
    Improved Garbled Circuit: Free XOR Gates and Applications Vladimir Kolesnikov1 and Thomas Schneider2? 1 Bell Laboratories, 600 Mountain Ave. Murray Hill, NJ 07974, USA [email protected] 2 Horst G¨ortzInstitute for IT-Security, Ruhr-University Bochum, Germany [email protected] Abstract. We present a new garbled circuit construction for two-party secure function evaluation (SFE). In our one-round protocol, XOR gates are evaluated \for free", which results in the corresponding improvement over the best garbled circuit implementations (e.g. Fairplay [19]). We build permutation networks [26] and Universal Circuits (UC) [25] almost exclusively of XOR gates; this results in a factor of up to 4 im- provement (in both computation and communication) of their SFE. We also improve integer addition and equality testing by factor of up to 2. We rely on the Random Oracle (RO) assumption. Our constructions are proven secure in the semi-honest model. 1 Introduction Two-party general secure function evaluation (SFE) allows two parties to evalu- ate any function on their respective inputs x and y, while maintaining privacy of both x and y. SFE is (justifiably) a subject of immense amount of research, e.g. [27,28,17]. Efficient SFE algorithms enable a variety of electronic transactions, previously impossible due to mutual mistrust of participants. Examples include auctions [21,6,8,4], contract signing [7], distributed database mining [12,16], etc. As computation and communication resources have increased, SFE has become truly practical for common use. Fairplay [19] is a full-fledged implementation of generic two-party SFE with malicious players.
    [Show full text]
  • Garbled Protocols and Two-Round MPC from Bilinear Maps
    58th Annual IEEE Symposium on Foundations of Computer Science Garbled Protocols and Two-Round MPC from Bilinear Maps Sanjam Garg Akshayaram Srinivasan Dept. of Computer Science Dept. of Computer Science University of California, Berkeley University of California, Berkeley Berkeley, USA Berkeley, USA Email: [email protected] Email: [email protected] Abstract—In this paper, we initiate the study of garbled (OT) protocol [57], [2], [51], [40] gives an easy solution to protocols — a generalization of Yao’s garbled circuits construc- the problem of (semi-honest) two-round secure computation tion to distributed protocols. More specifically, in a garbled in the two-party setting. However, the same problem for protocol construction, each party can independently generate a garbled protocol component along with pairs of input the multiparty setting turns out to be much harder. Beaver, labels. Additionally, it generates an encoding of its input. The Micali and Rogaway [7] show that garbled circuits can be evaluation procedure takes as input the set of all garbled used to realize a constant round multi-party computation protocol components and the labels corresponding to the input protocol. However, unlike the two-party case, this protocol encodings of all parties and outputs the entire transcript of the is not two rounds. distributed protocol. We provide constructions for garbling arbitrary protocols A. Garbled Protocols based on standard computational assumptions on bilinear maps (in the common random string model). Next, using In this paper, we introduce a generalization of Yao’s garbled protocols we obtain a general compiler that compresses construction from circuits to distributed protocols. We next any arbitrary round multiparty secure computation protocol elaborate on (i) what it means to garble a protocol, (ii) why into a two-round UC secure protocol.
    [Show full text]
  • Private Set Intersection: Are Garbled Circuits Better Than Custom Protocols?
    Private Set Intersection: Are Garbled Circuits Better than Custom Protocols? Yan Huang David Evans Jonathan Katz University of Virginia University of Maryland http://MightBeEvil.org Abstract PSI for post-processing). Many other examples are pro- vided by De Cristofaro et al. [9]. Cryptographic protocols for Private Set Intersection (PSI) Because of its importance and wide applicability, many are the basis for many important privacy-preserving ap- protocols for PSI and its variants have been proposed [7– plications. Over the past few years, intensive research has 11, 14, 15, 20, 24]. All these works develop custom PSI been devoted to designing custom protocols for PSI based protocols using asymmetric cryptography, usually with on homomorphic encryption and other public-key tech- the explicit remark that they do so because solving PSI niques, apparently due to the belief that solutions using via generic techniques (such as garbled-circuit proto- 1 generic approaches would be impractical. This paper ex- cols [39]) would be impractical. However, this claim has plores the validity of that belief. We develop three classes never been substantiated. of protocols targeted to different set sizes and domains, all The belief that generic techniques for solving PSI are based on Yao’s generic garbled-circuit method. We then inefficient may stem from several factors: a general feel- compare the performance of our protocols to the fastest ing that generic protocols are inherently slow and that custom PSI protocols in the literature. Our results show garbled circuits do not scale, or perhaps the belief that that a careful application of garbled circuits leads to solu- computing the intersection of two sets of size n requires tions that can run on million-element sets on typical desk- Q(n2)-size circuits since all pairs of elements must be tops, and that can be competitive with the fastest custom compared.
    [Show full text]
  • Reducing Garbled Circuit Size While Preserving Circuit Gate Privacy ⋆
    Reducing Garbled Circuit Size While Preserving Circuit Gate Privacy ? Yongge Wang1 and Qutaibah m. Malluhi2 1 Department of SIS, UNC Charlotte, USA [email protected] 2 Department of CS, Qatar University, Qatar [email protected] Abstract. Yao's garbled circuits have been extensively used in Secure Function Evaluations (SFE). Several improvements have been proposed to improve the efficiency of garbled circuits. Kolesnikov and Schneider (2008) proposed the free-XOR technique. Naor, Pinkas, and Sumner (1999) introduced garbled row-reduction technique GRR3 to reduce each garbled gate to three ciphertexts, Pinkas et al (2009) proposed GRR2, and Zahur, Rosulek, and Evans (2015) introduced a half-gates technique to design free-XOR compatible GRR2. The GRR2, half-gates, and free- XOR garbling schemes improve efficiency by leaking locations of XOR gates in the circuit. This kind of information leakage is acceptable for SFE protocols though it maybe be unacceptable for other protocols such as Private Function Evaluation (PFE). For example, these techniques could not be used to improve the efficiency of existing non-universal- circuit-based constant round PFE protocols. The first result of this paper is a Gate Privacy preserving Garbled Row Reduction technique GPGRR2 for designing garbled circuits with at most two ciphertexts for each gar- bled gate. Compared with state-of-the-art gate-privacy-preserving gar- bling scheme GRR3, the scheme GPGRR2 reduces the garbled circuit size by a factor of at least 33%. The second result is the design of a linear (over integers) garbling scheme to garble a single odd gate to one ciphertext. Zahur, Rosulek, and Evans (2015) proved that a linear gar- bling scheme garbles each odd gate to at least 2 ciphertexts.
    [Show full text]
  • A Gentle Introduction to Yao's Garbled Circuits
    A Gentle Introduction to Yao’s Garbled Circuits Sophia Yakoubov Boston Univeristy Abstract. This is a short, gentle introduction to the Yao’s Garbled Circuits construction and recent optimizations, as well as the garbled circuit definitions. Keywords: Yao’s Garbled Circuits Table of Contents Recap of Yao’s Garbled Circuits :::::::::::::::::::::::::::::::::::: 1 Sophia Yakoubov 1 Yao’s Garbled Circuits: Background..............................3 1.1 Classical Yao’s Garbled Circuits.............................3 Garbled Gate Generation...................................3 Garbled Gate Evaluation...................................3 From Gates to Circuits.....................................4 1.2 Optimizations to Yao’s Garbled Circuits......................4 Point and Permute........................................4 Free XOR [KS08]..........................................5 Garbled Row Reduction (GRR3) [NPS99]....................6 Garbled Row Reduction (GRR2) [PSSW09]...................6 FleXOR [KMR14].........................................7 Half Gates [ZRE15]........................................7 Garbled Gadgets [BMR16]..................................7 2 Yao’s Garbled Circuit Definitions................................9 2.1 Functionality.............................................9 2.2 Correctness...............................................9 2.3 Security..................................................9 1 Yao’s Garbled Circuits: Background 1.1 Classical Yao’s Garbled Circuits Let’s say two parties, Ginny and Evan, want to figure out
    [Show full text]
  • ASTRA: High Throughput 3PC Over Rings with Application to Secure Prediction∗
    ASTRA: High Throughput 3PC over Rings with Application to Secure Prediction∗ Harsh Chaudhari Ashish Choudhury† Indian Institute of Science, Bangalore India International Institute of Information Technology [email protected] Bangalore, India [email protected] Arpita Patra‡ Ajith Suresh Indian Institute of Science, Bangalore India Indian Institute of Science, Bangalore India [email protected] [email protected] Abstract in a way that no coalition of t parties can learn more information The concrete efficiency of secure computation has been the focus than the output (privacy) or affect the true output of the compu- of many recent works. In this work, we present concretely-efficient tation (correctness). While MPC, in general, has been a subject protocols for secure 3-party computation (3PC) over a ring of inte- of extensive research, the area of MPC with a small number of gers modulo 2` tolerating one corruption, both with semi-honest parties in the honest majority setting [4, 18, 20, 35, 56] has drawn and malicious security. Owing to the fact that computation over ring popularity of late mainly due to its efficiency and simplicity. Fur- emulates computation over the real-world system architectures, thermore, most real-time applications involve a small number of secure computation over ring has gained momentum of late. parties. Applications such as statistical and financial data analy- Cast in the offline-online paradigm, our constructions present sis [16], email-filtering [49], distributed credential encryption [56], the most efficient online phase in concrete terms. In the semi-honest Danish sugar beet auction [17] involve 3 parties.
    [Show full text]
  • Fast and Secure Three-Party Computation: the Garbled Circuit Approach
    Fast and Secure Three-party Computation: The Garbled Circuit Approach Payman Mohassel∗ Mike Rosuleky Ye Zhangz September 23, 2015 Abstract Many deployments of secure multi-party computation (MPC) in practice have used information- theoretic three-party protocols that tolerate a single, semi-honest corrupt party, since these protocols enjoy very high efficiency. We propose a new approach for secure three-party computation (3PC) that improves security while maintaining practical efficiency that is competitive with traditional information-theoretic protocols. Our protocol is based on garbled circuits and provides security against a single, malicious corrupt party. Unlike information-theoretic 3PC protocols, ours uses a constant number of rounds. Our protocol only uses inexpensive symmetric-key cryptography: hash functions, block ciphers, pseudorandom generators (in particular, no oblivious transfers) and has performance that is comparable to that of Yao's (semi- honest) 2PC protocol. We demonstrate the practicality of our protocol with an implementation based on the JustGarble framework of Bellare et al. (S&P 2013). The implementation incorporates various optimizations including the most recent techniques for efficient circuit garbling. We perform experiments on several benchmarking circuits, in different setups. Our experiments confirm that, despite providing a more demanding security guarantee, our protocol has performance comparable to existing information-theoretic 3PC. 1 Introduction Secure multi-party computation (MPC) allows a set of parties to compute a function of their joint inputs without revealing any information beyond the output of the function they compute. MPC has found nu- merous applications not only enabling various privacy-preserving tasks on sensitive data, but also removing a single point of attack by allowing for distribution of secrets and trust while maintaining the original func- tionality.
    [Show full text]
  • Banners: Binarized Neural Networks with Replicated Secret Sharing
    Banners: Binarized Neural Networks with Replicated Secret Sharing Alberto Ibarrondo Hervé Chabanne Melek Önen IDEMIA & EURECOM IDEMIA & Telecom Paris EURECOM Sophia Antipolis, France Paris, France Sophia Antipolis, France [email protected] ABSTRACT Making use of the deep learning toolbox comes at a non negligi- ble cost: one needs to acquire very large amounts of structured data, Binarized Neural Networks (BNN) provide efficient implementa- considerable computational power and vast technical expertise to tions of Convolutional Neural Networks (CNN). This makes them define and train the models. Subsequently, the expensively trained particularly suitable to perform fast and memory-light inference of deep learning models can be used to perform inference on data neural networks running on resource-constrained devices. Moti- not present during training. Naturally, risk arises when training or vated by the growing interest in CNN-based biometric recognition inference computation tasks are outsourced, following the trends on potentially insecure devices, or as part of strong multi-factor of Cloud Computing (where the model is sent to the cloud) or Edge authentication for sensitive applications, the protection of BNN Computing (where the trained model is pushed to edge devices inference on edge devices is rendered imperative. We propose a such as mobile phones or cars). In a standard setup, carrying out new method to perform secure inference of BNN relying on secure these processes on an outsourced enclave forces users to keep the multiparty computation. While preceding papers offered security model in plaintext to carry out mathematical operations, leading to in a semi-honest setting for BNN or malicious security for standard potential model theft and exposing all intermediate computations CNN, our work yields security with abort against one malicious as well as the input data and the inference result.
    [Show full text]
  • GMW Vs. Yao? Efficient Secure Two-Party Computation with Low
    GMW vs. Yao? Efficient Secure Two-Party Computation with Low Depth Circuits Thomas Schneider and Michael Zohner Engineering Cryptographic Protocols Group (ENCRYPTO), European Center for Security and Privacy by Design (EC SPRIDE), Technische Universit¨atDarmstadt, Germany fthomas.schneider,[email protected] Abstract. Secure two-party computation is a rapidly emerging field of research and enables a large variety of privacy-preserving applications such as mobile social networks or biometric identification. In the late eighties, two different approaches were proposed: Yao's garbled circuits and the protocol of Goldreich-Micali-Wigderson (GMW). Since then, re- search has mostly focused on Yao's garbled circuits as they were believed to yield better efficiency due to their constant round complexity. In this work we give several optimizations for an efficient implementa- tion of the GMW protocol. We show that for semi-honest adversaries the optimized GMW protocol can outperform today's most efficient im- plementations of Yao's garbled circuits, but highly depends on a low network latency. As a first step to overcome these latency issues, we summarize depth-optimized circuit constructions for various standard tasks. As application scenario we consider privacy-preserving face recog- nition and show that our optimized framework is up to 100 times faster than previous works even in settings with high network latency. Keywords: GMW protocol, optimizations, privacy-preserving face recognition 1 Introduction Generic secure two-party computation allows two parties to jointly compute any function on their private inputs without revealing anything but the result. Interestingly, two different approaches have been introduced at about the same time in the late eighties: Yao's garbled circuits [33] and the protocol of Goldreich- Micali-Wigderson (GMW) [11, 12].
    [Show full text]