Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Security of Trustee-based Social Authentications   Recently, authenticating users with the help of their friends (i.e.,
trustee-based social authentication) has been shown to be a promising backup
authentication mechanism. A user in this system is associated with a few
trustees that were selected from the user's friends. When the user wants to
regain access to the account, the service provider sends different verification
codes to the user's trustees. The user must obtain at least k (i.e., recovery
threshold) verification codes from the trustees before being directed to reset
his or her password.
  In this paper, we provide the first systematic study about the security of
trustee-based social authentications. Specifically, we first introduce a novel
framework of attacks, which we call forest fire attacks. In these attacks, an
attacker initially obtains a small number of compromised users, and then the
attacker iteratively attacks the rest of users by exploiting trustee-based
social authentications. Then, we construct a probabilistic model to formalize
the threats of forest fire attacks and their costs for attackers. Moreover, we
introduce various defense strategies. Finally, we apply our framework to
extensively evaluate various concrete attack and defense strategies using three
real-world social network datasets. Our results have strong implications for
the design of more secure trustee-based social authentications.

20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
3
The categories of this paper are: physics