Pith. sign in

REVIEW 4 major objections 5 minor 48 references

Privacy-Preserving Orthogonal Aggregation for Guaranteeing Gender Fairness in Federated Recommendation

T0 review · 4 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read This paper claims that gender fairness in federated recommendation can be achieved without leaking gender, by aggregating each gender's model updates in orthogonal subspaces, and that doing so improves recommendations for both genders.

desk verdict A solid, citable attack on F2MF's noise-based privacy and a neat orthogonal aggregation trick, but the privacy claim leans on an unstated TTP trust assumption. read the letter →

arxiv 2411.19678 v1 pith:VWUWEO2T submitted 2024-11-29 cs.LG

classification cs.LG
keywords federatedrecommendationgroupfairnessgendersecureaggregationorthogonalsensitiveattributeprivacyquantizationprivacy-preservingmachinelearning
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

Federated recommender systems let users train models without sharing raw data, but the paper argues that existing attempts to make them gender-fair fail twice: they only try to equalize performance across groups, ignoring data imbalance and preference disparity, and their noise-based privacy protection leaks gender (the authors recover it for 99.90% of users even at maximal noise). PPOA is their alternative: each gender's model update is mapped by a public bijection into a mutually orthogonal subspace of a doubled-dimensional space, all users' mapped vectors are summed under a secure-aggregation mask, and each user projects the sum back to obtain only their own group's average update. Because the server sees only random-looking masked vectors and the public attribute vectors, it learns neither the updates nor the gender labels. On three real-world datasets the method improves recommendation quality for females by up to 8.25% and males by up to 6.36%, with an overall gain of 7.30%, while giving the best gender-fairness gap in most settings. The paper positions PPOA as a way to preserve minority-group preferences instead of suppressing the majority group to force equal performance.

What carries the argument

The load-bearing object is the orthogonal embedding $F(\nu_i,\Theta_i^{(j)}) = (\theta_1\nu_i,\dots,\theta_d\nu_i)$ together with its inverse $F^{-1}(\nu_i,\mathbf{W}) = (\mathbf{W}_1\cdot\nu_i,\dots,\mathbf{W}_d\cdot\nu_i)$. Choosing $\nu_{\alpha}=(p,q)$ and $\nu_{\beta}=(-q,p)$ makes the two groups' embedded updates live in orthogonal subspaces, so a single sum of all masked embedded vectors contains each group's aggregate as a separate orthogonal component, extractable without the server knowing which user is which. Security comes from the SecAgg-style masks added before upload (generated by a trusted third party so they cancel in the server's sum) and quantization $Q_h$/$Q_h^{-1}$ reduces the doubled dimension back to the original communication cost. Theorem 1 is the correctness argument: for $v$ groups with pairwise-orthogonal attribute vectors that share a fixed inner product $\mu$, the inverse map recovers $\mu \sum_j \Theta_g^{(j)}$ for the user's own group $g$ and nothing from other groups.

What would settle it

Give the server the TTP's per-user mask records for a completed PPOA run on ML-1M and let it unmask one user's vector $\vartheta_i^{(j)}$; since the public attribute vectors satisfy $\nu_{\alpha}\cdot\nu_{\beta}=0$, testing which of the two vectors the unmasked embedding is orthogonal to reveals that user's gender, and repeating for all users settles whether the privacy guarantee survives TTP collusion.

Watch

Extended reading notes

Core claim

The central claim is that the federated aggregation step, not the local training loss, is where group unfairness is created, and that unfairness can be removed by separating the aggregation itself by group while keeping group membership secret. PPOA defines attribute vectors $\nu_{\alpha}=(p,q)$ and $\nu_{\beta}=(-q,p)$ in $\mathbb{R}^2$, maps each user's $d$-dimensional item embedding $\Theta_i^{(j)}$ to the $2d$-dimensional vector $(\theta_1\nu_i,\dots,\theta_d\nu_i)$, and has the server sum all such vectors (plus masks). Each user then projects the public sum onto their own attribute vector and rescales to obtain $\frac{1}{n_i}\sum_j \Theta_i^{(j)}$, the average update of their own gender group alone. Theorem 1 generalizes this to $v$ groups whenever the attribute vectors are pairwise orthogonal with a fixed inner product, so the scheme is not tied to binary gender. The paper further shows that combining this orthogonal aggregation with secure aggregation (masking via a trusted third party) and 16-bit quantization keeps the server unable to see updates and cancels the doubling of communication cost, with negligible accuracy loss.

Load-bearing premise

The load-bearing assumption is that the trusted third party generates and distributes the masks without knowing users' gender and never colludes with the server; if those masks leak or the TTP cooperates with the server, the server can unmask the orthogonal embeddings and recover the gender of every user.

Editorial extensions

If this is right

  • If PPOA works as claimed, federated recommenders can give minority users a model trained on their own group's preferences without the server ever receiving gender labels, removing the need to trade privacy for fairness.
  • The failure analysis implies that fairness constraints of the F2MF/F2PGNN type, which slow the advantaged group to match the disadvantaged one, are not just suboptimal but leak gender through the noisy group-count uploads; PPOA's masking avoids that channel.
  • Quantization at $h=16$ halves per-parameter bits, so the $2d$-dimensional embedding costs the same communication as the original $d$-dimensional upload, making the scheme practical under bandwidth limits.
  • Theorem 1 means the same protocol serves any number of groups and any sensitive attribute (age, region, and so on), not just binary gender.
  • The swap experiment (exchanging male and female model parameters at evaluation drops NDCG@10 by 28.62% on ML-100K) supports the claim that the two groups have genuinely different learned preferences, so separate aggregation is what preserves them.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A general pattern this suggests: any federated statistic that must be reported per subpopulation can be protected by the same trick of embedding each subpopulation into its own orthogonal subspace, as long as a trusted party can issue cancelling masks; this extends beyond recommendations to surveys, health dashboards, or ad measurements.
  • The attack results imply that differential-privacy-style noise bounds derived from utility constraints are not automatically privacy bounds; federated fairness mechanisms should be audited with threshold attacks like the one run here before being trusted.
  • A boundary condition the paper does not test: because orthogonal separation removes all inter-group information flow, its benefit likely depends on how distinct the groups' preferences really are; on more homogeneous populations the fusion coefficient $\gamma$ would matter more than the experiments suggest.
  • A scaling question left open: the scheme doubles the dimensionality to $2d$, so for very large item catalogs the per-user masking cost grows linearly; sparsifying the uploads, as the discussion mentions, is the natural next benchmark.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper addresses gender fairness in federated recommendation systems. It identifies three sources of unfairness—performance difference, data imbalance, and preference disparity—and argues that existing methods such as F2MF and F2PGNN only address the first. It then presents a privacy attack on F2MF's noisy group-statistic uploads, reporting 99.90% gender inference accuracy at the maximum noise level considered. The main proposal, Privacy-Preserving Orthogonal Aggregation (PPOA), maps each gender group's model updates into orthogonal subspaces via attribute vectors, aggregates the embedded vectors with a secure aggregation scheme, and uses quantization to offset the doubled communication cost. Experiments on ML-100K, ML-1M, and Foursquare-NYC compare PPOA with FedMF and F2MF, reporting improved recommendation performance for both genders and improved fairness on most datasets.

Significance. If the privacy guarantee can be made rigorous, PPOA is a worthwhile contribution: the orthogonal aggregation construction is elegant and makes group-specific aggregation compatible with server-side secure aggregation, and the attack on noise-based sensitive-attribute protection is concrete and empirically validated. The linear algebra behind Theorem 1 is simple and correct after fixing the statement. The main weakness is that the 'privacy-preserving' claim is not formally established: it relies on an unanalyzed trusted third party, and the paper provides no adversarial model or privacy proof. The experimental section supports the effectiveness claims only partially, because no error bars are provided and the ML-100K fairness result goes against the general fairness narrative.

major comments (4)
  1. [Sec. 5.3, Remark 1] The privacy guarantee is asserted rather than proven. The protocol delegates all mask generation to a single TTP, and the paper never states the adversarial model (e.g., honest-but-curious server that does not collude with the TTP) or provides an indistinguishability or simulation argument for the server's view. As written, if the TTP colludes with the server or is compromised, the server can subtract each user's mask and recover the masked attribute vector, thereby determining the user's gender with probability 1. Since 'privacy-preserving' is the headline contribution, this missing analysis is load-bearing; please state the trust assumptions explicitly, add a formal privacy proof under those assumptions, or redesign the protocol to avoid a single point of failure.
  2. [Theorem 1, Eq. (19)] The orthogonality condition is printed with the cases reversed: it requires ν_e·ν_f = 0 when e=f and μ otherwise, which is impossible for nonzero vectors and contradicts the two-group construction in Eq. (15) and the proof in Appendix B.2. The proof correctly uses self-dot μ and cross-dot 0. As printed, the central correctness theorem is false; the statement must be corrected to μ for e=f and 0 for e≠f.
  3. [Table 3 and Sec. 6.2] The claim that PPOA improves group fairness is not supported on ML-100K. In Table 3, PPOA's |E_male − E_female| is 0.0316 (HR@10) and 0.0051 (NDCG@10), larger than both FedMF (0.0128, 0.0011) and F2MF (0.0078, 0.0023). The abstract's 'optimal fairness in most cases' is a fair hedge, but the title and the Sec. 6.2 discussion ('it improves group fairness') overstate the result. Please report and analyze the tradeoff on ML-100K explicitly, or temper the fairness claims.
  4. [Sec. 6.1] The experiments are repeated 5 times but only averages are reported; no standard deviations, confidence intervals, or significance tests are provided. Given the headline improvements are 6–8%, it is not possible to assess whether they are statistically meaningful, especially on ML-100K where the fairness result is worse. Please add variance measures or significance tests.
minor comments (5)
  1. [Sec. 5.2] Calling F a bijection from R^d to R^{2d} is inaccurate; for fixed ν_i, F(ν_i,·) is an injective linear embedding. Please use 'embedding with left inverse' and define F^{-1} on the image subspace.
  2. [Sec. 5.3] The protocol does not discuss user dropout; with TTP-generated masks, dropout prevents mask cancellation. Please address this or cite a dropout-resilient variant of SecAgg.
  3. [Sec. 6.1] Please report the gender distribution for each dataset; the data-imbalance discussion in Fig. 1 is only shown for ML-1M.
  4. [Figures 3 and 6–9] Several figure axis labels and legends are garbled by font encoding; please regenerate them with embedded fonts so that the reported curves and legends are readable.
  5. [Sec. 7 and Appendix C] The group fusion coefficient γ is discussed as an extension but is not integrated with the main method; clarify whether it is part of PPOA or a future direction.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: empirical gains are measured, and the core algebraic theorem follows from the construction rather than from fitted or self-cited premises.

full rationale

The paper's central claims are (i) an orthogonal aggregation scheme that returns group-specific averages, (ii) empirical recommendation/fairness improvements, and (iii) privacy via secure aggregation. Claim (i) is proved in Theorem 1/Appendix B.2 as an algebraic identity using the definitions of F, F^{-1}, and orthogonality of attribute vectors. This is a construction-level correctness argument, not a prediction derived from fitted data, so it is not circular. Claim (ii) is an experimental comparison against FedMF and F2MF (Sec. 6.2); the reported 8.25%/6.36%/7.30% improvements are measured outcomes, and no parameter is fitted to force them. The privacy claim in Remark 1 and Sec. 5.3 is assumption-dependent: it relies on the external SecAgg protocol and on a non-colluding TTP that does not know gender. That reliance is a limitation/correctness risk rather than a circularity, because the paper does not define privacy in terms of its own conclusion, and the security argument is imported from Bonawitz et al. [3], not from the authors' own prior work. No load-bearing self-citations or renamed known results were found.

Assumptions & free parameters 2 free parameters · 4 assumptions · 1 invented entities

The central claim rests on the standard federated factorization model, the assumption that users know and truthfully report their gender, the honest-but-curious server plus trusted TTP model, and the chosen fairness metric. No parameters are fitted to data to make the method work; p, q, and h are design choices.

free parameters (2)
  • p, q (attribute vector coordinates) = randomly selected integers
    Define the orthogonal basis for the two groups. Any nonzero orthogonal pair works; correctness requires p^2+q^2 != 0. They do not affect empirical performance beyond a global scaling (division by p^2+q^2), so they are not fitted to data.
  • Quantization level h = 16
    Chosen to halve communication overhead. The paper shows (Fig. 8) that h=16 has negligible impact on accuracy, so it is not tuned to boost the reported results.
assumptions (4)
  • domain assumption The federated recommendation objective and loss function (Eq. 1) with implicit feedback.
    The method is built on the standard FedMF-style factorization model; results are only shown for this setup.
  • domain assumption Each user knows their own gender and truthfully selects the corresponding attribute vector.
    PPOA requires users to self-identify to pick nu_alpha or nu_beta. The paper does not address strategic users who might switch or misreport.
  • domain assumption The server is honest-but-curious and the TTP is trusted not to reveal masks or gender information.
    Privacy in Remark 1 depends on the security of SecAgg and the TTP. These assumptions are standard but not proven in this paper.
  • domain assumption Group fairness is measured by the absolute difference of average group performance metrics.
    This is the same metric used in F2MF; the paper does not justify it as the correct notion of fairness beyond prior convention.
invented entities (1)
  • Orthogonal attribute vectors (nu_alpha, nu_beta) independent evidence
    purpose: Map male and female model updates into orthogonal subspaces so a single secure aggregation can return group-specific averages without revealing individual group membership to the server.
    A mathematical construction introduced by this paper. Its correctness is proven in Theorem 1 and demonstrated in the experiments (Figs. 7 and 12). It is not a physical entity, but it is a new abstraction used by the method.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Privacy-Preserving Orthogonal Aggregation for Guaranteeing Gender Fairness in Federated Recommendation." pith.science (2026). https://pith.science/paper/VWUWEO2T

@misc{pith2026241119678,
  author       = {Pith},
  title        = {Pith review of: Privacy-Preserving Orthogonal Aggregation for Guaranteeing Gender Fairness in Federated Recommendation},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/VWUWEO2T}},
  note         = {Machine review of arXiv:2411.19678}
}
read the original abstract

Under stringent privacy constraints, whether federated recommendation systems can achieve group fairness remains an inadequately explored question. Taking gender fairness as a representative issue, we identify three phenomena in federated recommendation systems: performance difference, data imbalance, and preference disparity. We discover that the state-of-the-art methods only focus on the first phenomenon. Consequently, their imposition of inappropriate fairness constraints detrimentally affects the model training. Moreover, due to insufficient sensitive attribute protection of existing works, we can infer the gender of all users with 99.90% accuracy even with the addition of maximal noise. In this work, we propose Privacy-Preserving Orthogonal Aggregation (PPOA), which employs the secure aggregation scheme and quantization technique, to prevent the suppression of minority groups by the majority and preserve the distinct preferences for better group fairness. PPOA can assist different groups in obtaining their respective model aggregation results through a designed orthogonal mapping while keeping their attributes private. Experimental results on three real-world datasets demonstrate that PPOA enhances recommendation effectiveness for both females and males by up to 8.25% and 6.36%, respectively, with a maximum overall improvement of 7.30%, and achieves optimal fairness in most cases. Extensive ablation experiments and visualizations indicate that PPOA successfully maintains preferences for different gender groups.

Figures

Figures reproduced from arXiv: 2411.19678 by the authors.

Figure 1
Figure 1. Three gender-related phenomena in FRS. FedMF [5], a fundamental FRS, yields better recommendations for male users compared to female users on ML-1M dataset, (2) Data imbalance: as shown in [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 3
Figure 3. The percentage of exposed users among all users in [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 2
Figure 2. A diagram for identifying uploaded data of exposed [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figures from the paper (9 more)
Figure 4
Figure 4. Figure 4: A diagram of OA. Red represents females, and blue [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 5
Figure 5. Figure 5: The workflow of PPOA. We acknowledge that orthogonal aggregation does increase the number of parameters transmitted by users to the server from 𝑑 to 2𝑑, doubling the communication overhead. To this end, we employ quantization to eliminate the additional overhead. For e…
Figure 6
Figure 6. Figure 6: The respective recommendation performance (w.r.t. HR@10 and NDCG@10) for male and female groups compared to [PITH_FULL_IMAGE:figures/full_fig_p007_6.png]
Figure 7
Figure 7. Figure 7: The overall performance of PPOA across three [PITH_FULL_IMAGE:figures/full_fig_p007_7.png]
Figure 8
Figure 8. Figure 8: The overall performance of PPOA on ML-1M with [PITH_FULL_IMAGE:figures/full_fig_p007_8.png]
Figure 12
Figure 12. Figure 12: The t-SNE visualization of item embeddings for [PITH_FULL_IMAGE:figures/full_fig_p008_12.png]
Figure 10
Figure 10. Figure 10: The t-SNE visualization of item embeddings of [PITH_FULL_IMAGE:figures/full_fig_p008_10.png]
Figure 11
Figure 11. Figure 11: The t-SNE visualization of item embeddings of [PITH_FULL_IMAGE:figures/full_fig_p008_11.png]
Figure 13
Figure 13. Figure 13: The overall performance of PPOA with various [PITH_FULL_IMAGE:figures/full_fig_p011_13.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

48 extracted references · 31 canonical work pages

  1. [1]

    Nimesh Agrawal, Anuj Kumar Sirohi, Sandeep Kumar, et al. 2024. No Prejudice! Fair Federated Graph Neural Networks for Personalized Recommendation. In Proceedings of the AAAI Conference on Artificial Intelligence, Vol. 38. 10775–10783

  2. [2]

    Yoshinori Aono, Takuya Hayashi, Lihua Wang, Shiho Moriai, et al. 2017. Privacy- preserving deep learning via additively homomorphic encryption. IEEE Transac- tions on Information Forensics and Security 13, 5 (2017), 1333–1345

  3. [3]

    Keith Bonawitz, Vladimir Ivanov, Ben Kreuter, Antonio Marcedone, H. B. McMa- han, Sarvar Patel, Daniel Ramage, Aaron Segal, and Karn Seth. 2017. Practical Secure Aggregation for Privacy-Preserving Machine Learning. Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security (2017)

  4. [4]

    Yair Censor. 1977. Pareto optimality in multiobjective problems. Applied Mathe- matics and Optimization 4, 1 (1977), 41–59

  5. [5]

    Di Chai, Leye Wang, Kai Chen, and Qiang Yang. 2020. Secure federated matrix factorization. IEEE Intelligent Systems 36, 5 (2020), 11–20

  6. [6]

    Michael D Ekstrand, Anubrata Das, Robin Burke, and Fernando Diaz. 2012. Fair- ness in recommender systems. In Recommender systems handbook . Springer, 679–707

  7. [7]

    Adrian Flanagan, Were Oyomno, Alexander Grigorievskiy, Kuan E Tan, Suleiman A Khan, and Muhammad Ammad-Ud-Din. 2021. Federated multi-view matrix factorization for personalized recommendations. In Machine Learning and Knowledge Discovery in Databases: European Conference, ECML PKDD 2020, Ghent, Belgium, September 14–18, 2020, Proceedings, Part II . Springe...

  8. [8]

    Zuohui Fu, Yikun Xian, Ruoyuan Gao, Jieyu Zhao, Qiaoying Huang, Yingqiang Ge, Shuyuan Xu, Shijie Geng, Chirag Shah, Yongfeng Zhang, et al. 2020. Fairness- aware explainable recommendation over knowledge graphs. In Proceedings of the 43rd international ACM SIGIR conference on research and development in information retrieval. 69–78

Show all 48 references
  1. [9]

    Daniel Genkin, Itamar Pipman, and Eran Tromer. 2015. Get your hands off my laptop: physical side-channel key-extraction attacks on pcs: Extended version. Journal of Cryptographic Engineering 5 (2015), 95–112

  2. [10]

    Sahin Cem Geyik, Stuart Ambler, and Krishnaram Kenthapadi. 2019. Fairness- aware ranking in search & recommendation systems with application to linkedin talent search. In Proceedings of the 25th acm sigkdd international conference on knowledge discovery & data mining . 2221–2231

  3. [11]

    F Maxwell Harper and Joseph A Konstan. 2015. The movielens datasets: History and context. Acm transactions on interactive intelligent systems (tiis) 5, 4 (2015), 1–19

  4. [12]

    Harris, K

    Charles R. Harris, K. Jarrod Millman, Stéfan J. van der Walt, Ralf Gommers, Pauli Virtanen, David Cournapeau, Eric Wieser, Julian Taylor, Sebastian Berg, Nathaniel J. Smith, Robert Kern, Matti Picus, Stephan Hoyer, Marten H. van Kerkwijk, Matthew Brett, Allan Haldane, Jaime Fe...

  5. [13]

    Xiangnan He, Lizi Liao, Hanwang Zhang, Liqiang Nie, Xia Hu, and Tat-Seng Chua. 2017. Neural collaborative filtering. In Proceedings of the 26th international conference on world wide web . 173–182

  6. [14]

    Di Jin, Luzhi Wang, He Zhang, Yizhen Zheng, Weiping Ding, Feng Xia, and Shirui Pan. 2023. A survey on fairness-aware recommender systems. Information Fusion 100 (2023), 101906

  7. [15]

    Yehuda Koren, Robert Bell, and Chris Volinsky. 2009. Matrix factorization tech- niques for recommender systems. Computer 42, 8 (2009), 30–37

  8. [16]

    Thanh-Ha Le, Cécile Canovas, and Jessy Clédière. 2008. An overview of side channel analysis attacks. In Proceedings of the 2008 ACM Symposium on Infor- mation, Computer and Communications Security, ASIACCS 2008, Tokyo, Japan, March 18-20, 2008 , Masayuki Abe and Virgil D. Glig...

  9. [17]

    Yunqi Li, Yingqiang Ge, and Yongfeng Zhang. 2021. Tutorial on Fairness of Machine Learning in Recommender Systems. In SIGIR ’21: The 44th International ACM SIGIR Conference on Research and Development in Information Retrieval, Virtual Event, Canada, July 11-15, 2021 , Fernando...

  10. [18]

    Zhiwei Li, Guodong Long, and Tianyi Zhou. 2023. Federated recommendation with additive personalization. arXiv preprint arXiv:2301.09109 (2023)

  11. [19]

    Feng Liang, Weike Pan, and Zhong Ming. 2021. FedRec++: Lossless Federated Recommendation with Explicit Feedback. In Proceedings of the AAAI Conference on Artificial Intelligence. 4224–4231. https://doi.org/10.1609/AAAI.V35I5.16546

  12. [20]

    Guanyu Lin, Feng Liang, Weike Pan, and Zhong Ming. 2021. FedRec: Federated Recommendation With Explicit Feedback. IEEE Intell. Syst. 36, 5 (2021), 21–30. https://doi.org/10.1109/MIS.2020.3017205

  13. [21]

    Shuchang Liu, Yingqiang Ge, Shuyuan Xu, Yongfeng Zhang, and Amelie Marian

  14. [22]

    Ziyao Liu, Jiale Guo, Kwok-Yan Lam, and Jun Zhao. 2022. Efficient Dropout- Resilient Aggregation for Privacy-Preserving Machine Learning. IEEE Transac- tions on Information Forensics and Security 18 (2022), 1839–1854

  15. [23]

    Shiwei Lu, Ruihu Li, Wenbin Liu, Chaofeng Guan, and Xiaopeng Yang. 2023. Top-k sparsification with secure aggregation for privacy-preserving federated learning. Computers & Security 124 (2023), 102993

  16. [24]

    Sichun Luo, Yuanzhang Xiao, and Linqi Song. 2022. Personalized federated recommendation via joint representation learning, user clustering, and model adaptation. In Proceedings of the 31st ACM international conference on information & knowledge management. 4289–4293

  17. [25]

    Kiwan Maeng, Haiyu Lu, Luca Melis, John Nguyen, Mike Rabbat, and Carole-Jean Wu. 2022. Towards fair federated recommendation learning: Characterizing the inter-dependence of system and data heterogeneity. In Proceedings of the 16th ACM Conference on Recommender Systems . 156–167

  18. [26]

    Ladislav Malecek and Ladislav Peska. 2021. Fairness-preserving group recommen- dations with user weighting. In Adjunct Proceedings of the 29th ACM Conference on User Modeling, Adaptation and Personalization . 4–9

  19. [27]

    Brendan McMahan, Eider Moore, Daniel Ramage, Seth Hampson, and Blaise Aguera y Arcas. 2017. Communication-efficient learning of deep net- works from decentralized data. In Artificial intelligence and statistics . PMLR, 1273–1282

  20. [28]

    Vasileios Perifanis and Pavlos S Efraimidis. 2022. Federated neural collaborative filtering. Knowledge-Based Systems 242 (2022), 108441

  21. [29]

    Abdul Rehman, Imran Razzak, and Guandong Xu. 2022. Federated learning for privacy preservation of healthcare data from smartphone-based side-channel attacks. IEEE Journal of Biomedical and Health Informatics 27, 2 (2022), 684–690

  22. [30]

    Raphael Spreitzer, Veelasha Moonsamy, Thomas Korak, and Stefan Mangard

  23. [31]

    Cong Su, Guoxian Yu, Jun Wang, Hui Li, Qingzhong Li, and Han Yu. 2024. Multi- Dimensional Fair Federated Learning. In Proceedings of the AAAI Conference on Artificial Intelligence , Michael J. Wooldridge, Jennifer G. Dy, and Sriraam Natarajan (Eds.). 15083–15090. https://doi.o...

  24. [32]

    Laurens Van der Maaten and Geoffrey Hinton. 2008. Visualizing data using t-SNE. Journal of machine learning research 9, 11 (2008)

  25. [33]

    Paul Voigt and Axel Von dem Bussche. 2017. The eu general data protection reg- ulation (gdpr). A Practical Guide, 1st Ed., Cham: Springer International Publishing 10, 3152676 (2017), 10–5555

  26. [34]

    Huanyu Wang and Elena Dubrova. 2021. Federated learning in side-channel analysis. In Information Security and Cryptology–ICISC 2020: 23rd International Conference, Seoul, South Korea, December 2–4, 2020, Proceedings 23 . Springer, 257–272

  27. [35]

    Yifan Wang, Weizhi Ma, Min Zhang, Yiqun Liu, and Shaoping Ma. 2023. A survey on the fairness of recommender systems. ACM Transactions on Information Systems 41, 3 (2023), 1–43

  28. [36]

    Zachary Weinberg, Eric Y Chen, Pavithra Ramesh Jayaraman, and Collin Jackson

  29. [37]

    Chuhan Wu, Fangzhao Wu, Lingjuan Lyu, Tao Qi, Yongfeng Huang, and Xing Xie. 2022. A federated graph neural network framework for privacy-preserving personalization. Nature Communications 13, 1 (2022), 3091

  30. [38]

    Liqiang Wu, Ming Xu, Shaojing Fu, Yuchuan Luo, and Yuechuan Wei. 2022. FPDA: Fault-Tolerant and Privacy-Enhanced Data Aggregation Scheme in Fog- Assisted Smart Grid. IEEE Internet of Things Journal 9 (2022), 5254–5265. https: //api.semanticscholar.org/CorpusID:239720384

  31. [39]

    Dingqi Yang, Daqing Zhang, Vincent W Zheng, and Zhiyong Yu. 2014. Modeling user activity preference by leveraging user spatial temporal characteristics in LBSNs. IEEE Transactions on Systems, Man, and Cybernetics: Systems 45, 1 (2014), 129–142

  32. [40]

    Han Yu, Zelei Liu, Yang Liu, Tianjian Chen, Mingshu Cong, Xi Weng, Dusit Niyato, and Qiang Yang. 2020. A sustainable incentive scheme for federated learning. IEEE Intelligent Systems 35, 4 (2020), 58–69

  33. [41]

    Chunxu Zhang, Guodong Long, Tianyi Zhou, Peng Yan, Zijian Zhang, Chengqi Zhang, and Bo Yang. 2023. Dual Personalization on Federated Recommendation. In Proceedings of the Thirty-Second International Joint Conference on Artificial Intelligence, IJCAI 2023, 19th-25th August 2023...

  34. [42]

    Zhiyuan Zhao and Gauri Joshi. 2022. A Dynamic Reweighting Strategy For Fair Federated Learning. In IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2022, Virtual and Singapore, 23-27 May 2022 . IEEE, 8772–8776. https://doi.org/10.1109/ICASSP4392...

  35. [43]

    Yifeng Zheng, Shangqi Lai, Yi Liu, Xingliang Yuan, Xun Yi, and Cong Wang

  36. [48]

    IEEE Transactions on Dependable and Secure Computing 20, 2 (2022), 988–1001

    Aggregation service for federated learning: An efficient, secure, and more resilient realization. IEEE Transactions on Dependable and Secure Computing 20, 2 (2022), 988–1001. Conference’17, July 2017, Washington, DC, USA Siqing Zhang et al. ETHICAL CONSIDERATIONS PPOA has no p...

  37. [2011]

    In 2011 IEEE Symposium on Security and Privacy

    I still know what you visited last summer: Leaking browsing history via user interaction and side channel attacks. In 2011 IEEE Symposium on Security and Privacy. IEEE, 147–161

  38. [2018]

    IEEE Communications Surveys & Tutorials 20, 1 (2018), 465–488

    Systematic Classification of Side-Channel Attacks: A Case Study for Mobile Devices. IEEE Communications Surveys & Tutorials 20, 1 (2018), 465–488

  39. [2022]

    In Proceedings of the 16th ACM conference on recommender systems

    Fairness-aware federated matrix factorization. In Proceedings of the 16th ACM conference on recommender systems . 168–178

  40. [4566]

    https://doi.org/10.24963/IJCAI.2023/507

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.