Cognitive radio (CR) technology has been suggested for effective use of spectral resources. Spectrum sensing is one of the main operations of CR users to identify the vacant frequency bands. Cooperative spectrum sensing (CSS) is used to increase the performance of CR networks by providing spatial diversity. The accuracy of spectrum sensing is the most important challenge in the CSS process sinc...

Nowadays, malicious URLs are the common threat to the businesses, social networks, net-banking etc. Existing approaches have focused on binary detection i.e. either the URL is malicious or benign. Very few literature is found which focused on the detection of malicious URLs and their attack types. Hence, it becomes necessary to know the attack type and adopt an effective countermeasure. This pa...

Widespread use of the SSH protocol greatly reduces the risk of remote computer access by encoding the transmission of clear text usernames and passwords. Prior to the use of SSH, packet sniffing, which allows malicious users to watch for the login process in the clear text packet traffic on a network segment, was an easy method for a malicious user to gain unauthorized access to a machine. Unfo...

Cognitive radio is a revolutionary paradigm to migrate the spectrum scarcity problem in wireless networks. In cognitive radio networks, collaborative spectrum sensing is considered as an effective method to improve the performance of primary user detection. For current collaborative spectrum sensing schemes, secondary users are usually assumed to report their sensing information honestly. Howev...

In this paper, we consider reliable cooperative spectrum sensing in cognitive networks under the Spectrum Sensing Data Falsification (SSDF) attacks. One effective method to mitigate the SSDF attacks is the q-out-of-m fusion scheme, where the final decision is based on q sensing reports from m polled users. In this paper, first, we derive the asymptotic behavior of the fusion scheme as the netwo...

Mobile code refers to programs that come into a host computer over the network and start to execute with or without a user’s knowledge or consent. Because these programs run in the execution context of the user that downloads them, they can issue any system calls that the user is allowed to make, and thus pose a serious security threat when they are malicious. Although many solutions have been ...

As has recently been demonstrated, a malicious third party could insert a self-issued CA public key into the list of trusted root CA public keys stored on an end user PC. As a consequence, the malicious third party could potentially do severe damage to the end user computing environment. In this paper, we discuss the problem of fake root public keys and suggest a solution that can be used to de...

One major difficulty faced by organizations is the protection of data against malicious access. Six security mechanisms, namely, authentication, authorization, access control, auditing, encryption and integrity control are available in Oracle 10g database management systems (DBMS). These are implemented for protecting data. These typical database security mechanisms are not able to detect and h...

We consider the problem of characterizing user equilibria and optimal solutions for selfish routing in a given network. We extend the known models by considering malicious behaviour. While selfish users follow a strategy that minimizes their individual cost, a malicious user will use his flow through the network in an effort to cause the maximum possible damage to this cost. We define a general...

Hypertext transfer protocol (HTTP) has become the main protocol to carry out malicious activities. Attackers typically use HTTP for communication with command-and-control servers, click fraud, phishing and other malicious activities, as they can easily hide among the large amount of benign HTTP traffic. The useragent (UA) field in the HTTP header carries information on the application, operatin...