Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Post-Training Detection of Backdoor Attacks for Two-Class and
  Multi-Attack Scenarios   Backdoor attacks (BAs) are an emerging threat to deep neural network
classifiers. A victim classifier will predict to an attacker-desired target
class whenever a test sample is embedded with the same backdoor pattern (BP)
that was used to poison the classifier's training set. Detecting whether a
classifier is backdoor attacked is not easy in practice, especially when the
defender is, e.g., a downstream user without access to the classifier's
training set. This challenge is addressed here by a reverse-engineering defense
(RED), which has been shown to yield state-of-the-art performance in several
domains. However, existing REDs are not applicable when there are only {\it two
classes} or when {\it multiple attacks} are present. These scenarios are first
studied in the current paper, under the practical constraints that the defender
neither has access to the classifier's training set nor to supervision from
clean reference classifiers trained for the same domain. We propose a detection
framework based on BP reverse-engineering and a novel {\it expected
transferability} (ET) statistic. We show that our ET statistic is effective
{\it using the same detection threshold}, irrespective of the classification
domain, the attack configuration, and the BP reverse-engineering algorithm that
is used. The excellent performance of our method is demonstrated on six
benchmark datasets. Notably, our detection framework is also applicable to
multi-class scenarios with multiple attacks. Code is available at
https://github.com/zhenxianglance/2ClassBADetection.

22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci