Multilaterally Secure Ubiquitous Auditing

Abstract

Tracking information of individuals is a useful input to many Ubiquitous Computing (UbiComp) applications. Consider the example of a smart emergency management application: once mobile first responders are continuously tracked, a precise and safe coordination of rescue missions is possible, and also mission logs can be created for audit purposes. However, continuously tracking users and storing the data for later use is often in conflict with individual privacy preferences. This may ultimately lead to the non-acceptance and rejection of these new technologies by their users. In order to reconcile privacy and accountability requirements in location tracking systems, we introduce and evaluate the approach of using auditing mechanisms on two levels. We illustrate that, by employing carefully designed cryptographic mechanisms for selective pseudonym linkability based on efficient techniques of secure multiparty computation, it is possible to balance the conflicting interests to a certain extent. Our work, motivated by and applied to smart emergency management systems, is a step towards the realization of multilaterally secure and thus multilaterally acceptable UbiComp systems supporting collaborative work.

A novel policy-driven reversible anonymisation scheme for XML-based services

“…This scenario has the same weakness as the other pseudonymisers, since it may be vulnerable to trac analysis attacks in the intervals between rekeying of the pseudonymiser. Some of the ideas in this scheme have been extended to support multilaterally secure ubiquitous auditing in [27,26]. It combines transaction pseudonyms based on threshold cryptography with secure multiparty computations to support secure and privacy enhanced tracking of mobile rescue units.…”

Sybil-Free Pseudonyms, Privacy and Trust: Identity Management in the Internet of Services

“…A traceable signature scheme 26) , which is a group signature scheme with additional tracing capabilities 3) , can be used as a cryptographic primitive to set up privacy-friendly X.509 attribute certificates that can provide unlinkability between different appearances of the same attribute certificate 5) . Semantically secure encryption can be used to generate changeable pseudonyms 43) . Changeable transaction pseudonyms, which are represented by ciphertexts, were presented in 42).…”

MundoMessage

“…Also, we assume that potential receivers of messages continuously provide location information to the system. In order to deal with the inherent privacy issues [20,21] of this situation, we propose that location tracking proceeds under transaction pseudonyms. Yet, we also provide a technique for reidentification of role or specialization attributes implicitly attached to pseudonyms.…”

“…First, in order to generate transaction pseudonyms, a base pseudonym PU i ,B of a user Ui is initially created as an ElGamal encryption of an algebraic representation of the unique base identifier IDi (cp. [20,21]). Thus, ID ∈ Gq is non-deterministically encrypted by choosing r ∈R Zq and by computing (g r , h r IDi).…”

“…In the architecture displayed infigure 3, this authority is represented by the re-identification module 9. A distributed implementation of the LB is also possible using techniques presented in[21]. For simplicity, we describe the single authority version.…”