scholarly journals Efficient Private Set Intersection Using Point-Value Polynomial Representation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ou Ruan ◽  
Hao Mao
Keyword(s):  
Formal Proof ◽  
Contact Tracing ◽  
Experimental Result ◽  
Polynomial Representation ◽  
Set Intersection ◽  
Wide Range ◽  
System 2 ◽  
Roots Of Polynomials ◽  
Private Set Intersection ◽  
Pseudorandom Function

Private set intersection (PSI) allows participants to securely compute the intersection of their inputs, which has a wide range of applications such as privacy-preserving contact tracing of COVID-19. Most existing PSI protocols were based on asymmetric/symmetric cryptosystem. Therefore, keys-related operations would burden these systems. In this paper, we transform the problem of the intersection of sets into the problem of finding roots of polynomials by using point-value polynomial representation, blind polynomials’ point-value pairs for secure transportation and computation with the pseudorandom function, and then propose an efficient PSI protocol without any cryptosystem. We optimize the protocol based on the permutation-based hash technique which divides a set into multisubsets to reduce the degree of the polynomial. The following advantages can be seen from the experimental result and theoretical analysis: (1) there is no cryptosystem for data hiding or encrypting and, thus, our design provides a lightweight system; (2) with set elements less than 212, our protocol is highly efficient compared to the related protocols; and (3) a detailed formal proof is given in the semihonest model.

ROTed: Random Oblivious Transfer for embedded devices

2021 ◽  
pp. 215-238
Author(s):  
P. Branco ◽  
L. Fiolhais ◽  
M. Goulão ◽  
P. Martins ◽  
P. Mateus ◽  
...  
Keyword(s):  
State Of The Art ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Oblivious Transfer ◽  
The State ◽  
Contact Tracing ◽  
Embedded Devices ◽  
Set Intersection ◽  
Wide Range ◽  
Order Of Magnitude

Oblivious Transfer (OT) is a fundamental primitive in cryptography, supporting protocols such as Multi-Party Computation and Private Set Intersection (PSI), that are used in applications like contact discovery, remote diagnosis and contact tracing. Due to its fundamental nature, it is utterly important that its execution is secure even if arbitrarily composed with other instances of the same, or other protocols. This property can be guaranteed by proving its security under the Universal Composability model. Herein, a 3-round Random Oblivious Transfer (ROT) protocol is proposed, which achieves high computational efficiency, in the Random Oracle Model. The security of the protocol is based on the Ring Learning With Errors assumption (for which no quantum solver is known). ROT is the basis for OT extensions and, thus, achieves wide applicability, without the overhead of compiling ROTs from OTs. Finally, the protocol is implemented in a server-class Intel processor and four application-class ARM processors, all with different architectures. The usage of vector instructions provides on average a 40% speedup. The implementation shows that our proposal is at least one order of magnitude faster than the state-of-the-art, and is suitable for a wide range of applications in embedded systems, IoT, desktop, and servers. From a memory footprint perspective, there is a small increase (16%) when compared to the state-of-the-art. This increase is marginal and should not prevent the usage of the proposed protocol in a multitude of devices. In sum, the proposal achieves up to 37k ROTs/s in an Intel server-class processor and up to 5k ROTs/s in an ARM application-class processor. A PSI application, using the proposed ROT, is up to 6.6 times faster than related art.

Provably Secure Contact Tracing with Conditional Private Set Intersection

2021 ◽  
pp. 352-373
Author(s):  
Jonathan Takeshita ◽  
Ryan Karl ◽  
Alamin Mohammed ◽  
Aaron Striegel ◽  
Taeho Jung
Keyword(s):  
Contact Tracing ◽  
Set Intersection ◽  
Private Set Intersection ◽  
Provably Secure

scholarly journals PCT-TEE: Trajectory-based Private Contact Tracing System with Trusted Execution Environment

2022 ◽  
Vol 8 (2) ◽  
pp. 1-35
Author(s):  
Fumiyuki Kato ◽  
Yang Cao ◽  
Mastoshi Yoshikawa
Keyword(s):  
Direct Contact ◽  
Homomorphic Encryption ◽  
Infected Individual ◽  
Contact Tracing ◽  
Trajectory Data ◽  
Indirect Contact ◽  
Set Intersection ◽  
Execution Environment ◽  
Private Set Intersection ◽  
Trusted Execution Environment

Existing Bluetooth-based private contact tracing (PCT) systems can privately detect whether people have come into direct contact with patients with COVID-19. However, we find that the existing systems lack functionality and flexibility , which may hurt the success of contact tracing. Specifically, they cannot detect indirect contact (e.g., people may be exposed to COVID-19 by using a contaminated sheet at a restaurant without making direct contact with the infected individual); they also cannot flexibly change the rules of “risky contact,” such as the duration of exposure or the distance (both spatially and temporally) from a patient with COVID-19 that is considered to result in a risk of exposure, which may vary with the environmental situation. In this article, we propose an efficient and secure contact tracing system that enables us to trace both direct contact and indirect contact. To address the above problems, we need to utilize users’ trajectory data for PCT, which we call trajectory-based PCT . We formalize this problem as a spatiotemporal private set intersection that satisfies both the security and efficiency requirements. By analyzing different approaches such as homomorphic encryption, which could be extended to solve this problem, we identify the trusted execution environment (TEE) as a candidate method to achieve our requirements. The major challenge is how to design algorithms for a spatiotemporal private set intersection under the limited secure memory of the TEE. To this end, we design a TEE-based system with flexible trajectory data encoding algorithms. Our experiments on real-world data show that the proposed system can process hundreds of queries on tens of millions of records of trajectory data within a few seconds.

Profile Matching for IoMT: A Verifiable Private Set Intersection Scheme

2021 ◽  
pp. 1-1
Author(s):  
Yalian Qian ◽  
Jian Shen ◽  
Pandi Vijayakumar ◽  
Pradip Kumar Sharma
Keyword(s):  
Profile Matching ◽  
Set Intersection ◽  
Private Set Intersection

Simplified coupling power model for fibers fusion

2009 ◽  
Vol 17 (3) ◽  
Author(s):  
J. Saktioto ◽  
J. Ali ◽  
M. Fadhali
Keyword(s):  
Refractive Index ◽  
Propagation Constant ◽  
Tunable Filter ◽  
Experimental Result ◽  
Total Power ◽  
Optical Parameters ◽  
Coupling Region ◽  
Ratio Distribution ◽  
Hydrogen Flow ◽  
Wide Range

AbstractFiber coupler fabrication used for an optical waveguide requires lossless power for an optimal application. The previous research coupled fibers were successfully fabricated by injecting hydrogen flow at 1 bar and fused slightly by unstable torch flame in the range of 800–1350°C. Optical parameters may vary significantly over wide range physical properties. Coupling coefficient and refractive index are estimated from the experimental result of the coupling ratio distribution from 1% to 75%. The change of geometrical fiber affects the normalized frequency V even for single mode fibers. V is derived and some parametric variations are performed on the left and right hand side of the coupling region. A partial power is modelled and derived using V, normalized lateral phase constant u, and normalized lateral attenuation constant, w through the second kind of modified Bessel function of the l order, which obeys the normal mode and normalized propagation constant b. Total power is maintained constant in order to comply with the energy conservation law. The power is integrated through V, u, and w over the pulling length of 7500 µm for 1-D. The core radius of a fiber significantly affects V and power partially at coupling region rather than wavelength and refractive index of core and cladding. This model has power phenomena in transmission and reflection for an optical switch and tunable filter.

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