Scalable Private Set Union, with Stronger Security

Private Set Union (PSU) protocol allows parties, each holding an input set, to jointly compute the union of the sets without revealing anything else. In the literature, scalable PSU protocols follow the “split-execute-assemble” paradigm (Kolesnikov et al., ASIACRYPT 2019); in addition, those fast protocols often use Oblivious Transfer as building blocks. Kolesnikov et al. (ASIACRYPT 2019) and Jia et al. (USENIX Security 2022), pointed out that certain security issues can be introduced in the “split-execute-assemble” paradigm. In this work, surprisingly, we observe that the typical way of invoking Oblivious Transfer also causes unnecessary leakage, and only the PSU protocols based on additively homomorphic encryption (AHE) can avoid the leakage. However, the AHE-based PSU protocols are far from being practical. To bridge the gap, we also design a new PSU protocol that can avoid the unnecessary leakage. Unlike the AHE-based PSU protocols, our new construction only relies on symmetric-key operations other than base OTs, thereby being much more scalable. The experimental results demonstrate that our protocol can obtain at least 873.74× speedup over the best-performing AHE-based scheme. Moreover, our performance is comparable to that of the state-of-the-art PSU protocol (Chen et al., USENIX Security 2023), which also suffers from the unnecessary leakage

The Ideal Functionalities for Private Set Union, Revisited

A Private Set Union (PSU) protocol allows parties, each holding an input set, to jointly compute the union of the sets without revealing anything else. In the literature, when we design scalable two-party PSU protocols, we follow the so-called ``split-execute-assemble\u27\u27 paradigm, and also use Oblivious Transfer as a building block. Recently, Kolesnikov et al. (ASIACRYPT 2019) pointed out that security issues could be introduced when we design PSU protocols following the ``split-execute-assemble\u27\u27 paradigm. Surprisingly, we observe that the typical way of invoking Oblivious Transfer also causes unnecessary leakage. In this work, to enable a better understanding of the security for PSU, we provide a systematic treatment of the typical PSU protocols, which may shed light on the design of practical and secure PSU protocols in the future. More specifically, we define different versions of PSU functionalities to properly capture the subtle security issues arising from protocols following the ``split-execute-assemble\u27\u27 paradigm and using Oblivious Transfer as subroutines. Then, we survey the typical PSU protocols, and categorize these protocols into three design frameworks, and prove what PSU functionality the protocols under each framework can achieve at best, in the semi-honest setting

Shuffle-based Private Set Union: Faster and More Secure

Private Set Union ($\mathsf{PSU}$) allows two players, the sender and the receiver, to compute the union of their input datasets without revealing any more information than the result. While it has found numerous applications in practice, not much research has been carried out so far, especially for large datasets. In this work, we take shuffling technique as a key to design $\mathsf{PSU}$ protocols for the first time. By shuffling receiver\u27s set, we put forward the first protocol, denoted as $\Pi_{\mathsf{PSU}}^{\mathsf{receiver}}$, that eliminates the expensive operations in previous works, such as additive homomorphic encryption and repeated operations on the receiver\u27s set. It outperforms the state-of-the-art design by Kolesnikov et al. (ASIACRYPT 2019) in both efficiency and security; the unnecessary leakage in Kolesnikov et al.\u27s design, can be avoided in our design. We further extend our investigation to the application scenarios in which both players may hold unbalanced input datasets. We propose our second protocol $\Pi_{\mathsf{PSU}}^{\mathsf{sender}}$, by shuffling the sender\u27s dataset. This design can be viewed as a dual version of our first protocol, and it is suitable in the cases where the sender\u27s input size is much smaller than the receiver\u27s. Finally, we implement our protocols $\Pi_{\mathsf{PSU}}^{\mathsf{receiver}}$ and $\Pi_{\mathsf{PSU}}^{\mathsf{sender}}$ in C++ on big datasets, and perform a comprehensive evaluation in terms of both scalability and parallelizability. The results demonstrate that our design can obtain a $4$-$5 \times$ improvement over the state-of-the-art by Kolesnikov et al. with a single thread in WAN/LAN settings

How recipient firms benefit from international joint ventures : resource and knowledge transfer, learning mechanisms and technology spillovers in the China context

This research contributes to the literature on resource, knowledge and capability transfer in international joint ventures. In mainstream international business literature, few empirical studies have been undertaken at the micro-organization level on the extent to which, and ways in which recipients benefit from the resources and knowledge transferred from the foreign partner in an IJV. This study explores the transfer content, context, process and effects from the recipient’s perspective. Measures of the acquisition/learning intentions of the recipient firm and the transfer benefits, including transfer channels and learning mechanisms, are drawn from a synthesis of international business, international management, knowledge management and knowledge transfer and learning literature. A business function-related knowledge typology by Pak and Park (2004) among a number of other knowledge typologies was adapted to specifically examine the types and extent of resources and knowledge transferred from the foreign partner to the recipient firm among four Sino-foreign IJVs in the auto parts and animal feed sectors. They were compared using quantitative and qualitative measures of the types and levels of acquisition and learning intentions, the transfer benefits within and outside the IJVs, and transfer channels and learning mechanisms they have developed. The findings highlighted the micro-organization processes of transfer and learning in IJVs that bring together parent firms from very different business contexts. Firstly, the ‘alignment’ or ‘fit’ between the source and recipient in the JV partnership influences the nature and level of resulting benefits. The measures of ‘success’ vary from firm to firm, being strongly influenced by the learning intentions in line with the initial level of resources, experience and knowledge of the recipient firm. Cross-sector differences, especially the combination impact of different levels of Chinese Government departments on the learning intentions and transfer benefits were revealed. Transfer channels and learning mechanisms vary according to the type of knowledge that is transferred, and the source and recipient firms’ particular organizational characteristics. The recipient firm’s organizational development strategy, aspects of wider organizational absorptive capacity and the motives of individuals were found to be important in facilitating technological spillovers and counteracting the foreign partner’s efforts to protect certain knowledge and processes. Overall, this research adds insights to previous studies of IJVs by emphasizing the context-specific nature of the transfer and acquisition/learning intentions, processes and outcomes

Corporate hybrids and the co-evolution of institutions and enterprise in China

Chapter 6 introduces two variants of 'hybrid' enterprises in China that reflect both the institutional factors influencing modes of firm operations and how the behaviors of hybrids can be reflected in enterprises' progress in china

Can information of chemical reaction propagate with plasmonic waveguide and be detected at remote terminal of nanowire?

We attempt to provide experimental and theoretical evidence that information of chemical reaction can propagate with plasmonic waveguide along the nanowire and be detected at the remote terminal of nanowire, where the chemical reaction is the surface catalyzed reaction of DMAB produced from PATP assisted by surface plasmon polaritons

Institutional drivers of stakeholder engagement and legitimacy of Chinese MNEs

Chinese multinational enterprises (MNEs) have adopted aggressive internationalization strategies in recent years. Despite their impressive success, Chinese MNEs have encountered serious and prolonged legitimating challenges of East-meets-West. This study draws upon the stakeholder view and institutional theory to examine the linkages between stakeholder engagement and the organizational legitimacy of Chinese MNEs in Western countries. We submit that home-host country institutional distances (regulatory, cognitive and normative) underscore stakeholder engagement deficiencies of and local distrust toward Chinese MNEs which in turn are detrimental to their establishment of organizational legitimacy in Western host countries. By distinguishing between sub-national and national legitimacy, we reveal the differential effects of some intervening remedies such as isomorphism and stakeholder negotiation adopted by the Chinese MNEs