Biblio

Cloud-hosted applications are prone to targeted attacks such as DDoS, advanced persistent threats, cryptojacking which threaten service availability. Recently, methods for threat information sharing and defense require co-operation and trust between multiple domains/entities. There is a need for mechanisms that establish distributed trust to allow for such a collective defense. In this paper, we present a novel threat intelligence sharing and defense system, namely “DefenseChain”, to allow organizations to have incentive-based and trustworthy co-operation to mitigate the impact of cyber attacks. Our solution approach features a consortium Blockchain platform to obtain threat data and select suitable peers to help with attack detection and mitigation. We propose an economic model for creation and sustenance of the consortium with peers through a reputation estimation scheme that uses `Quality of Detection' and `Quality of Mitigation' metrics. Our evaluation experiments with DefenseChain implementation are performed on an Open Cloud testbed with Hyperledger Composer and in a simulation environment. Our results show that the DefenseChain system overall performs better than state-of-the-art decision making schemes in choosing the most appropriate detector and mitigator peers. In addition, we show that our DefenseChain achieves better performance trade-offs in terms of metrics such as detection time, mitigation time and attack reoccurence rate. Lastly, our validation results demonstrate that our DefenseChain can effectively identify rational/irrational service providers.

Two-factor authentication (2FA) is widely prevalent in banking, emails and virtual private networks (VPN) connections or in accessing any secure web service. In 2FA, to get authenticated the users are expected to provide additional secret information along with the password. Typically, this secret information (tokens) is generated by a centralized trusted third party upon receiving an authentication request from users. Thus, this additional layer of security comes at the cost of inherently trusting the third party for their services. The security of such authentication systems is always under the threat of the trusted party is being compromised. In this paper, we propose a novel approach to make server authentication even more secure by building 2FA over the blockchain platform which is distributed in nature. The proposed solution does not require any trusted third party between claimant (user) and the verifier (server) for the authentication purpose. To demonstrate the idea of using blockchain technology for 2FA, we have added an extra layer of security component to the OpenSSH server a widely used application for Secure Shell (SSH) protocol.