Cláudio José Pereira Correia

Co-advisor: M. Pupo Correia

Omega: a Secure Event Ordering Service for the Edge

Tese submetida para provas de mestrado em Engenharia Informática e de Computadores Instituto Superior Técnico, Universidade de Lisboa.


Edge computing is a paradigm that extends cloud computing with storage and processing capacity close to the edge of the network, with the aim of supporting latency sensitive applications such as augmented reality or mobile gaming. Edge computing is often materialized by using many fog servers that are deployed in small data centers, placed in multiple geographic locations. Fog nodes are likely to be more vulnerable to tampering than nodes placed in large central data centers and, therefore, it is important to secure the functions they provide from malicious faults.

A key building block of many distributed applications is an ordering service, that is able to keep track of cause-effect dependencies among events and that allows events to be processed in an order that respects causality. In this thesis we present the design and implementation of a secure event ordering service for fog nodes. Our service, named Omega, leverages the availability of a Trusted Execution Environment (TEE), namely of the Intel SGX enclave, to offer to fog clients guarantees regarding the order by which events are applied and served, even when the fog nodes become compromised. To assess the performance of our techniques, we have built a key-value store that offers causal consistency for the edge that makes extensive use of Omega. Experimental results show that, despite the overhead associated with the use of the TEE, the ordering service can be secured without violating the latency constraints of time-sensistive edge applications.


Omega: a Secure Event Ordering Service for the Edge
Cláudio José Pereira Correia
MSc Thesis. Instituto Superior Técnico, Universidade de Lisboa.
November, 2019.
Available BibTeX, MSC Thesis, and extended abstract, and mid-term report.
Ordenação Segura de Eventos na Periferia da Rede.
C. Correia, L. Rodrigues and M. Correia
Actas do décimo primeiro Simpósio de Informática (Inforum), Guimarães, Portugal, Sep. 2019.
Available BibTeX, extended report (pdf).
Omega: a Secure Event Ordering Service for the Edge.
C. Correia, L. Rodrigues, and M. Correia.
Proceedings of 50th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN 2020), Valência, Spain, June 2020.

Luís Rodrigues