Cyberspace, the ubiquitous space that exists in relation to the Internet, is usually referred to as a dynamic broad domain ranging from Internet and its infrastructures to social networks. More research work in security has been extended from securing computers to securing Cyberspace, which includes the physical-level security, the network-level security, and the application-level security and addresses improvements in Cyberspace management.As a result, recent years have witnessed increasing research attention on securing Cyberspace, and many interesting methods have been proposed to locate suspicious IP, detect gossip content, prevent illegal information publication and distribution, manage social software and applications, and profile user behavior and opinion. This trend has provided the motivation to launch this special issue. The papers in this issue report a variety of methods used to tackle the security issues in cyberspace. They aim at improving security in applications ranging from RFID systems, location based service, discovery of software vulnerability to private medical records, and outsourcing in Multi-Cloud. The problems discussed in these papers are also related to disciplines including data mining, network security, digital forensics, and behavioral and psychological sciences.Here, we provide an integrative perspective of this special issue by summarizing each contribution contained therein.In [1], to address security and privacy issue in RFID systems, a new off-line reading orderindependent grouping-proof protocol is proposed to generate a proof that a group of tags have been scanned simultaneously in the range of a reader. The proposed protocol defines an ideal groupingproof functionality aiming at capturing the secure grouping-proof generation for a group of RFID tags in the UC framework. The new protocol maintains its security properties when composed concurrently with an unbounded number of instances of arbitrary protocol. In addition, the protocol conforms to the computational constraints of EPC Class-Gen-2 passive RFID tags. It is suitable for low-cost passive RFID tags, which are widely used in practical applications.In [2], the authors proposed an algorithm to address the problem of preserving privacy for individual users in location-aware applications. They define a novel distance measurement that combines the semantic and Euclidean distance to address the privacy-preserving issue. They conduct performance experiments on the proposed algorithm and distance metric, and results suggest that they can successfully retain the utility of the location services.In [3], to discover software vulnerability, an effective and efficient mechanism is proposed. The method also helps programmers to write secure code to avoid the existence of vulnerability at the early stage of software development. The proposed mechanism uses code clone verification to discover vulnerability in software programs and reduces the false positive of detection by combining the advantages of static and dynamic analysis. In ad...