Showing papers by "Gene Tsudik published in 1989"

Visa protocols for controlling interorganizational datagram flow

Abstract: The increasing use of internetworking protocols to connect administratively heterogeneous networks has raised the question of how an organization can control the flow of information across its network boundaries. One method for doing so is the use of visas, a cryptographic technique for authenticating and authorizing a flow of datagrams. Two visa protocols are presented and evaluated: one that requires distributed state information in gateways and one that uses additional encryptions instead of distributed state. Applications for such visa protocols include access control, accounting and billing for packet transit, and network resource management. >

Security issues in policy routing

Abstract: Most routing protocols, including proposed policy routing protocols, focus on environments where detection of an attack after it has taken place is sufficient. The authors explore the design of policy routing mechanisms for sensitive environments where more aggressive preventative measures are mandated. In particular, they detail the design of four secure protocol versions that prevent abuse by cryptographic checks of data integrity. They analyze and compare these schemes in terms of their prepacket processing overhead. It is concluded that preventative security is feasible, although the overhead cost is quite high. Consequently, it is critical that prevention-based schemes coexist with detection-based schemes. >

Datagram authentication in internet gateways: implications of fragmentation and dynamic routing

Abstract: The implications of fragmentation and dynamic routing for datagram authentication at the gateway level are discussed. Two protocols are presented that permit varying degrees of fragmentation and dynamic routing, while allowing the gateways to authenticate successive packets belonging to authorized connections. The first adapts to changing paths and fragmentation by keeping state information on a per-packet basis, while the second restricts fragmentation but incurs little state overhead. The two methods vary in implementation complexity, overhead, number of extra packets sent, and host modification requirements. They were designed with different network characteristics in mind, and, since they are not mutually exclusive, both can be incorporated and used depending on the nature of communication. >