Paper 2006/140

GVG-RP: A Net-centric Negligibility-based Security Model for Self-organizing Networks

Jiejun Kong

Abstract

We present a rigorous approach to building a secure self-organizing mobile ad hoc network (MANET). In a highly dynamic environment like MANET, it is impossible to ensure absolute security to protect everything. We have to speak of the "infeasibility" of breaking the security system rather than the "impossibility" of breaking the same system. More formally, security is defined on the concept of "negligible", which is asymptotically sub-polynomial with respect to a pre-defined system parameter $n$. Intuitively, the parameter $n$ in modern cryptography is the key length. The crypto-system's security is broken if the adversary's capability is of exponentials of $n$, and the efficiency of all related algorithms is measured in polynomials of $n$. We adopt the same formal security notion in ad hoc network security research. In network security, the network scale (i.e., number of network members) $N$ replaces the role of key length $n$ in cryptography. If a security scheme can be devised to ensure that the probability of security failure is negligible, then the larger the network scale is or the more complex the network system is, the more secure the network is. In other words, given a negligibility-based protection against a specific security attack, larger or more complex systems are favored over smaller or simpler systems. Intuitively, this is consistent with the evolution theory where more complex entities probabilistically emerge from and likely survive longer than their less complex counterparts. In this paper, we use ``rushing attack'' as the exemplary security attack to disrupt mobile ad hoc routing. We show that ``rushing attack'' is a severe attack against on-demand ad hoc routing schemes. Fortunately, ``localized forwarding community area'' is an available countermeasure to ensure that the failure probability of packet forwarding is negligible. This demonstrates the usefulness of our negligibility-based network security model. We expect to augment the pool of negligibility-based protections and explore the general notion in other types of networks.\\ \emph{Keywords}---Net-centric Security = Negligibility + Scalability

Note: This paper defines the first formal security model using network scale as the input parameter of negligibility. The model is for network-centric security, not limited to cryptography.