Lucia Draque Penso

TrustedPals: secure multiparty computation implemented with smart cards

We study the problem of Secure Multi-party Computation (SMC) in a model where individual processes contain a tamper-proof security module, and introduce the TrustedPals framework, an efficient smart card based implementation of SMC for any number of participating entities in such a model. Security modules can be trusted by other processes and can establish secure channels between each other. However, their availability is restricted by their host, that is, a corrupted party can stop the computation of its own security module as well as drop any message sent by or to its security module. We show that in this model SMC can be implemented by reducing it to a fault-tolerance problem at the level of security modules. Since the critical part of the computation can be executed locally on the smart card, we can compute any function securely with a protocol complexity which is polynomial only in the number of processes (that is, the complexity does not depend on the function which is computed), in contrast to previous approaches.

Efficient reduction for wait-free termination detection in a crash-prone distributed system

We investigate the problem of detecting termination of a distributed computation in systems where processes can fail by crashing. Specifically, when the communication topology is fully connected, we describe a way to transform any termination detection algorithm

Relating stabilizing timing assumptions to stabilizing failure detectors regarding solvability and efficiency

\mathcal{A}

Secure failure detection in TrustedPals

that has been designed for a failure-free environment into a termination detection algorithm

Complexity analysis of P 3 -convexity problems on bounded-degree and planar graphs

\mathcal{B}

The south zone: distributed algorithms for alliances

that can tolerate process crashes. Our transformation assumes the existence of a perfect failure detector. We show that a perfect failure detector is in fact necessary to solve the termination detection problem in a crash-prone distributed system even if at most one process can crash. Let μ(n,M) and δ(n,M) denote the message complexity and detection latency, respectively, of

From crash-stop to permanent omission: automatic transformation and weakest failure detectors

\mathcal{A}

On termination detection in crash-prone distributed systems with failure detectors

when the system has n processes and the underlying computation exchanges M application messages. The message complexity of

Complexity properties of complementary prisms

\mathcal{B}

Immediate versus eventual conversion: comparing geodetic and hull numbers in P 3 -convexity

is at most O(n + μ(n,0)) messages per failure more than the message complexity of