Cyber security in home and small office local area networks - Attack vectors and vulnerabilities

This thesis presents security issues and vulnerabilities in home and small office local area networks that can be used in cyber-attacks. There is previous research done on single vulnerabilities and attack vectors, but not many papers present full scale attack examples towards LAN. First this thesis categorizes different security threads and later in the paper methods to launch the attacks are shown by example. Offensive security and penetration testing is used as research methods in this thesis. As a result of this thesis an attack is conducted using vulnerabilities in WLAN, ARP protocol, browser as well as methods of social engineering. In the end reverse shell access is gained to the target machine. Ready-made tools are used in the attack and their inner workings are described. Prevention methods are presented towards the attacks in the end of the thesis.

Aspectos do gerenciamento de riscos de tecnologia da informação nas empresas: um estudo de caso múltiplos

The information technology - IT- benefits have been more perceived during the last decades. Both IT and business managers are dealing with subjects like governance, IT-Business alignment, information security and others on their top priorities. Talking about governance, specifically, managers are facing it with a technical approach, that gives emphasis on protection against invasions, antivirus systems, access controls and others technical issues. The IT risk management, commonly, is faced under this approach, that means, has its importance reduced and delegated to IT Departments. On the last two decades, a new IT risk management perspective raised, bringing an holistic view of IT risk to the organization. According to this new perspective, the strategies formulation process should take into account the IT risks. With the growing of IT dependence on most of organizations, the necessity of a better comprehension about the subject becomes more clear. This work shows a study in three public organizations of the Pernambuco State that investigates how those organizations manage their IT risks. Structured interviews were made with IT managers, and later, analyzed and compared with conceptual categories found in the literature. The results shows that the IT risks culture and IT governance are weakly understood and implemented on those organizations, where there are not such an IT risk methodology formally defined, neither executed. In addition, most of practices suggested in the literature were found, even without an alignment with an IT risks management process

Batch Verification of Validity of Bids in Homomorphic E-auction

Bid opening in e-auction is efficient when a homomorphic secret sharing function is employed to seal the bids and homomorphic secret reconstruction is employed to open the bids. However, this high efficiency is based on an assumption: the bids are valid (e.g., within a special range). An undetected invalid bid can compromise correctness and fairness of the auction. Unfortunately, validity verification of the bids is ignored in the auction schemes employing homomorphic secret sharing (called homomorphic auction in this paper). In this paper, an attack against the homomorphic auction in the absence of bid validity check is presented and a necessary bid validity check mechanism is proposed. Then a batch cryptographic technique is introduced and applied to improve the efficiency of bid validity check.

A Multiplicative Homomorphic Sealed-Bid Auction-Based on Goldwasser-Micali Encryption

Instead of the costly encryption algorithms traditionally employed in auction schemes, efficient Goldwasser-Micali encryption is used to design a new sealed-bid auction. Multiplicative homomorphism instead of the traditional additive homomorphism is exploited to achieve security and high efficiency in the auction. The new scheme is the currently known most efficient non-interactive sealed-bid auction with bid privacy.

Using coloured petri nets to simulate DoS-resistant protocols

In this work, we examine unbalanced computation between an initiator and a responder that leads to resource exhaustion attacks in key exchange protocols. We construct models for two cryp-tographic protocols; one is the well-known Internet protocol named Secure Socket Layer (SSL) protocol, and the other one is the Host Identity Protocol (HIP) which has built-in DoS-resistant mechanisms. To examine such protocols, we develop a formal framework based on Timed Coloured Petri Nets (Timed CPNs) and use a simulation approach provided in CPN Tools to achieve a formal analysis. By adopting the key idea of Meadows' cost-based framework and re¯ning the de¯nition of operational costs during the protocol execution, our simulation provides an accurate cost estimate of protocol execution compar- ing among principals, as well as the percentage of successful connections from legitimate users, under four di®erent strategies of DoS attack.