Bootstrapping Secure Multicast using Kerberized Multimedia Internet Keying

We address bootstrapping secure multicast in enterprise and public-safety settings. Our work is motivated by the fact that secure multicast has important applications in such settings, and that the application setting significantly influences the design of security systems and protocols. This document presents and analyzes two designs for the composition of the authentication protocol, Kerberos, and the key transport protocol, Multimedia Internet KEYing (MIKEY). The two designs are denoted to be KM1 and KM2 . The main aspect in which the objective impacts the design is the assumption of an additional trusted third party (called a Key Server) that is the final arbiter on whether a principal is authorized to receive a key. Secure composition can be a challenge, and therefore the designs were kept to be simple so they have intuitive appeal. Notwithstanding this, it was recognized that even simple, seemingly secure protocols can have flaws. Two main security properties of interest called safety and avail- ability were articulated. A rigorous analysis of KM1 and KM2 was conducted using Protocol Composition Logic (PCL), a symbolic approach to analyzing security protocols, to show that the designs have those properties. The value of the analysis is demonstrated by a possible weakness in KM1 that was discovered which lead to the design of KM2 . A prototype of KM1 and KM2 was implemented starting with the publicly available reference implementation of Kerberos, and an open-source implementation of MIKEY. This document also discusses the experience from the implementation, and present empirical results which demonstrate the inherent trade-off between security and performance in the design of KM1 and KM2

Security aspects of OSPF as a MANET routing protocol

OSPF, Open Shortest Path First, is an Intra-gateway routing protocol first developed as an IETF effort. It is widely adopted in large enterprise-scale networks, being well regarded for its fast convergence and loop-free routing. It is versatile in terms of which interface types it supports, such as point-to-point links or broadcast networks. It also offers scalability through hierarchical routing and by using centralization to reduce the amount of overhead on networks which have broadcast or broadcast-similar properties. An interface type missing from the standard so far is that of a wireless network, characterized by non-guaranteed bidirectional links combined with unreliable broadcasting, and existing interface types generally perform poorly under these networks. The IETF has therefore instituted a Working Group to standardize such an interface type extension to the latest version, OSPF version 3. This interface type will permit mobility and multi-hop characteristics in addition to those of wireless links in general. Such networks are usually referred to as Mobile Ad-hoc Networks (MANET). MANET routing protocols are subject to more severe security issues than ordinary, wireline-oriented protocols are. This thesis aims to indentify key security aspects of OSPF as a MANET routing protocol

Journal of Telecommunications and Information Technology, 2014, nr 3

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Efficient Kerberized Multicast in a Practical Distributed Setting

Many of today's distributed applications are based on group communication. Given the openness of today's networks, communication among group members must be secure and, at the same time, efficient. In this paper we consider a realistic distributed setting modeling general networks, including the Internet, that suggests the use of Kerberos, and, more specifically, a distributed mode of operation of Kerberos, called crossrealm authentication protocol, as a desirable choice for distributed applications. We design an efficient protocol for secure group communication via multicast, using Kerberos. While developing the main components of our protocol, we construct an efficient paradigm for crossrealm authentication protocols that decreases communication over the Internet, makes most operations local, and reduces the workload of the involved components. We also design extensions of single-center multicast encryption schemes to multiple-center schemes. Our main protocol is obtained by combining these two contributions