Biblio

Lack of effective accountability mechanisms brings a series of security problems for Internet today. In Next Generation Internet based on IPv6, the system of identity authentication and IP verification is the key to accounting ability. Source Address Validation Improvement (SAVI) can protect IP source addresses from being faked. But without identity authentication mechanism and certain relationship between IP and accountable identity, the accountability is still unreliable. To solve this problem, most research focus on embedding accountable identity into IP address which need either changing DHCP client or twice DHCP request process due to the separate process of user authentication and address assignment. Different from previous research, this paper first analyzes the problems and requirements of combining Web Portal or 802.1X, two main identity authentication mechanism (AAA), with the accountable address assignment in SAVI frame-work. Then a novel Cooperative mechanism for Accountable IP address assignment (CAIP) is proposed based on 802.1X and SAVI, which takes into account the validation of IP address, the authenticity and accountability of identity at the same time. Finally, we build up prototype system for both Fat AP and Thin AP wireless scenarios and simulate the performance of CAIP through large-scale campus networks' data logs. The experiment result shows that the IP addresses and identities in CAIP are protective and accountable. Compared with other previous research, CAIP is not only transparent to the terminals and networks, but also low impact on network equipment, which makes CAIP easy deployment with high compatibility and low cost.

Network attacks have become a growing threat to the current Internet. For the enhancement of network security and accountability, it is urgent to find the origin and identity of the adversary who misbehaves in the network. Some studies focus on embedding users' identities into IPv6 addresses, but such design cannot support the Stateless Address Autoconfiguration (SLAAC) protocol which is widely deployed nowadays. In this paper, we propose SDN-Ti, a general solution to traceback and identification for attackers in IPv6 networks based on Software Defined Network (SDN). In our proposal, the SDN switch performs a translation between the source IPv6 address of the packet and its trusted ID-encoded address generated by the SDN controller. The network administrator can effectively identify the attacker by parsing the malicious packets when the attack incident happens. Our solution not only avoids the heavy storage overhead and time synchronism problems, but also supports multiple IPv6 address assignment scenarios. What's more, SDN-Ti does not require any modification on the end device, hence can be easily deployed. We implement SDN-Ti prototype and evaluate it in a real IPv6 testbed. Experiment results show that our solution only brings very little extra performance cost, and it shows considerable performance in terms of latency, CPU consumption and packet loss compared to the normal forwarding method. The results indicate that SDN-Ti is feasible to be deployed in practice with a large number of users.