SF-APP: A Secure Framework for Authentication and Privacy Preservation in Opportunistic Networks

Introduction

Opportunistic networks (OppNets) have evolved as a special class of mobile ad-hoc and delay tolerant networks which have a vast range of applications including disaster and rescue networks (Lilien, Gupta, & Yang, 2007), wildlife monitoring (Sadler & Martonosi, 2004), social networking DakNet (Pentland, Fletcher, & Hasson, 2004), PodNet (“PodNet - Mobile Distribution of User-generated Content [PodNet Project],” n.d.), Haggle (Nordström, Rohner, & Gunningberg, 2014) to name a few. In OppNets, end-to-end connectivity among the nodes is absent. OppNets use receive-carry-forward routing mechanism instead of receive-forward (W. Wang, Guo, Zheng, Tang, & Wang, 2015). Due to diverse features, such as intermittent connectivity, seed deployment, different routing mechanism, mobility, delay tolerant nature, OppNets have many security concerns. Security solutions designed for traditional wireless and ad-hoc networks cannot be directly applied to OppNets, as they have different unique features.

A variety of communication technologies are used in OppNets. These devices may vary in communication, computational and energy resources. Mobility and frequent link disruption make OppNets topology even more dynamic and flexible. In OppNets no direct path exists between the source and destination. So, the nodes have to hold the data with themselves till the next communication opportunity is found. Thus, the data moves closer to destination hop by hop. Hence trust becomes very important as if any node behaves maliciously then network performance may be degraded by a huge factor. Even whole network can be disrupted, since the malicious node can temper with the original message or can replace the whole message by putting bogus/wrong information. Due to various factors discussed and adaptive nature, it is crucial to provide good privacy and security in opportunistic network, not only for the classical use cases but also when considering emerging application paradigms such as mobile sensing and opportunistic computing (Trifunovic et al., 2017). Additionally, user privacy is another important issue in OppNets, as users own their personal devices. Since many routing protocols use context information; this may be sensitive to some users. This implies the necessity of a security solution which can cope up with the specific requirements of OppNets.

In this paper, we addressed these issues and proposed an authentication and incentive based secure framework that prevents unauthorized users from accessing sensitive information, maintains the confidentiality of data, preserves the privacy of users and helps to develop trust among the users. Our proposed framework (SF-APP) has the mechanism for authentication, privacy preservation and trust management. The design objectives of SF-APP are:

• 1.

  To design an authentication and encryption mechanism that prevent the unauthorized users from accessing the vital information as well as ensure the confidentiality and integrity of data;

• 2.

  To design an incentive scheme that gives the special benefits to the legitimate users and helps to develop the trust among the users.

The main contributions of this paper are:

• 1.

  Proposed secure framework SF-APP (Secure Framework for Authentication and Privacy Preservation);

• 2.

  Authentication using dynamic IDs;

• 3.

  Trust based forwarding mechanism;

• 4.

  Security analysis of proposed framework.

Opportunistic Network Security

In this section, we described specific challenges, threats and security requirements and threats concerned with OppNets.