Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Boosting Privately: Privacy-Preserving Federated Extreme Boosting for
  Mobile Crowdsensing   Recently, Google and other 24 institutions proposed a series of open
challenges towards federated learning (FL), which include application expansion
and homomorphic encryption (HE). The former aims to expand the applicable
machine learning models of FL. The latter focuses on who holds the secret key
when applying HE to FL. For the naive HE scheme, the server is set to master
the secret key. Such a setting causes a serious problem that if the server does
not conduct aggregation before decryption, a chance is left for the server to
access the user's update. Inspired by the two challenges, we propose FedXGB, a
federated extreme gradient boosting (XGBoost) scheme supporting forced
aggregation. FedXGB mainly achieves the following two breakthroughs. First,
FedXGB involves a new HE based secure aggregation scheme for FL. By combining
the advantages of secret sharing and homomorphic encryption, the algorithm can
solve the second challenge mentioned above, and is robust to the user dropout.
Then, FedXGB extends FL to a new machine learning model by applying the secure
aggregation scheme to the classification and regression tree building of
XGBoost. Moreover, we conduct a comprehensive theoretical analysis and
extensive experiments to evaluate the security, effectiveness, and efficiency
of FedXGB. The results indicate that FedXGB achieves less than 1% accuracy loss
compared with the original XGBoost, and can provide about 23.9% runtime and
33.3% communication reduction for HE based model update aggregation of FL.

20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org