Generating Unlinkable IPv6 Addresses

A number of approaches to the automatic generation of IPv6 addresses have been proposed with the goal of preserving the privacy of IPv6 hosts. However, existing schemes for address autoconfiguration do not adequately consider the full context in which they might be implemented, in particular the impact of low quality random number generation. This can have a fundamental impact on the privacy property of unlinkability, one of the design goals of a number of IPv6 address autoconfiguration schemes. In this paper, the potential shortcomings of previously proposed approaches to address autoconfiguration are analysed in detail, focussing on what happens when the assumption of strong randomness does not hold. Practical improvements are introduced, designed to address the identified issues by making the random generation requirements more explicit, and by incorporating measures into the schemes designed to ensure adequate randomness is used.