Alysson Bessani's Personal Page

I'm an associate professor at the Informatics Department of Faculdade de Ciências da Universidade de Lisboa, on Lisbon, Portugal. I'm also member of LaSIGE (Large Scale Informatics Systems Laboratory) group where I'm involved in several research projects with the Navigators team. I've spent the Summer of 2014 at Microsoft Research Cambridge, working in the Systems and Network Group. I've also spent the Spring 2010 semester on leave to Carnegie Mellon University's CyLab working in the PDL (Parallel Data Lab).

"Those who fall in love with Practice without Theory are like the seaman on a boat without a steering wheel or a compass, who is never sure where he'll land."
(Leonardo da Vinci)

"Anyone can make the simple complicated. Creativity is making the complicated simple."
(Charles Mingus)

New and Noteworthy

·       Here are three blockchain presentations I gave in 2018: Blockchain for Dummies (Teclabs), Experiences with BFT-SMaRt as a consensus substrate of Permissioned Ledgers (IFIP WG 10.4 Meeting), Permissioned Ledgers: Consensus is only the Beginning (CHAIN-IN'18).

·       I'm involved in a new data storage startup called vawlt. We leverage the concept of cloud-of-clouds, introduced in DepSky, to implement the most secure cloud storage service :-)

·       I'm involved in a three blockchain-related events in the next months: BCBR'18 (with DSN'18, in Luxembourg), CHAIN-IN'18 (Porto, PT), SERIAL'18 (with Middleware'18, in Rennes, FR).

·       I received an IBM Faculty Award to work on the Hyperledger Fabric blockchain project. A key objectives of the collaboration is to integrate BFT-SMaRt as an ordering layer for the framework. Check our paper on DSN'18 and code for Fabric 1.2.

·       I'm coordinating the DiSIEM H2020 project about security monitoring. I'm really excited to work on a bunch of new topics (OSINT processing, machine learning, security metrics, etc.) with great partners! Check our webpage.

·       Our work on BFT-SMaRt (a complete and fully maintained BFT and CFT replication library) is gaining a lot of momentum due to the popularization of permissioned block chains. Check our paper describing the system. I gave a tutorial on EuroSys'12 and wrote a book chapter about the state machine replication and this system.

·       I'm coordinating the IRCoC (Intelligent Replication in Cloud-of-Clouds) project (between July 2016 and June 2019 - funded by FCT). We will be evolving ideas from previous works like DepSky, SCFS and WHEAT to improve adaptability and scalability of wide-area replication protocols.


Research Interests: Distributed Systems, Fault Tolerance, and Security.

Selected and Recent Papers (full list, Google scholar profile)

Eduardo Viegas, Altair Santin, Alysson Bessani, Nuno Neves. BigFlow: Real-time and Reliable Anomaly-based Intrusion Detection for High-Speed Networks. Future Generation Computer Systems. Accepted in September 2018.

João Sousa, Alysson Bessani, Marko Vukolic. A Byzantine Fault-Tolerant Ordering Service for the Hyperledger Fabric Blockchain Platform. DSN'18: The IEEE/IFIP International Conference on Dependable Systems and Networks. June 2018. pdf (makes obsolete previous arXiv tech. report)

Paulo Coelho, Tarcisio Ceolin, Alysson Bessani, Fernando Dotti, Fernando Pedone. Byzantine Fault-Tolerant Atomic Multicast. DSN'18: The IEEE/IFIP International Conference on Dependable Systems and Networks. June 2018. pdf

André Nogueira, Miguel Garcia, Alysson Bessani, Nuno Neves. On the challenges of building a BFT SCADA. DSN'18: The IEEE/IFIP International Conference on Dependable Systems and Networks. June 2018. pdf

Miguel Garcia, Nuno Neves, Alysson Bessani. SieveQ: A Layered BFT Protection System for Critical Services. IEEE Transactions on Dependable and Secure Computing. Vol. 15, Num. 3. IEEE Computer Society. May-June 2018. preprint IEEE link

Wilson Melo Jr, Luiz F. R. C. Carmo, Alysson Bessani, Nuno Neves, Altair Santin. How Blockchains can improve Measuring Instruments Regulation and Control. I2MTC'18: The IEEE International Instrumentation and Measurement Technology Conference. May 2018. pdf

Carlos Carvalho, Daniel Porto, Luís Rodrigues, Manuel Bravo, Alysson Bessani. Dynamic Adaptation of Byzantine Consensus Protocols. SAC'18: The ACM/SIGApp Symposium on Applied Computing (DADS track). April 2018. pdf

Eduardo Adilio Pelinson Alchieri, Alysson Bessani, Fabíola Greve, Joni da Silva Fraga. Knowledge Connectivity Requirements for Solving Byzantine Consensus with Unknown Participants. IEEE Transactions on Dependable and Secure Computing. Vol. 15, Num. 2. IEEE Computer Society. March-April 2018. preprint IEEE link (A preliminar version appeared on OPODIS’08).

Eduardo Alchieri, Alysson Bessani, Fabiola Greve, Joni Fraga. Efficient and Modular Consensus-Free Reconfiguration for Fault-Tolerant Storage. OPODIS’17: The 21st International Conference On Principles Of DIstributed Systems. Lisbon, Portugal, December 2017. pdf (extended version on arXiv)

Joel Alcântara, Tiago Oliveira, Alysson Bessani. Ginja: One-dollar Cloud-based Disaster Recovery for Databases. Middleware’17: The ACM/IFIP/USENIX Middleware Conference. Las Vegas, USA, December 2017. pdf

Andre Nogueira, Antonio Casimiro, Alysson Bessani. Elastic State Machine Replication. IEEE Transactions on Parallel and Distributed Systems. Vol. 28, Num. 9. IEEE Computer Society. September 2017. preprint IEEE link

Tiago Oliveira, Ricardo Mendes, Alysson Bessani. Exploring Key-Value Stores in Multi-Writer Byzantine-Resilient Register Emulations. OPODIS’16: The 20th International Conference On Principles Of DIstributed Systems. Madrid, Spain, December 2016. pdf

Fábio Botelho, Tulio A. Ribeiro, Paulo Ferreira, Fernando M. V. Ramos, Alysson Bessani. Design and Implementation of a Consistent Datastore for a Distributed SDN Control Plane. EDCC’16: The 12th European Conference on Dependable Computing. Gothenburg, Sweden, September 2016. pdf (A preliminar version appeared on EWSDN’13).

João Sousa, Alysson Bessani. Separating the WHEAT from the Chaff: An Empirical Design for Geo-Replicated State Machines. SRDS'15: The 34th International Symposium on Reliable Distributed Systems. Montreal, Quebec, Canada. Sep. 2015. pdf

Tobias Distler, Christopher Bahn, Alysson Bessani, Frank Fischer, Flavio Junqueira. Extensible Distributed Coordination. EuroSys'15: The 10th ACM SIGOPS/EuroSys European Systems Conference. Bordeux, France. April 2015. pdf software.

Alysson Bessani, Ricardo Mendes, Tiago Oliveira, Nuno Neves, Miguel Correia, Marcelo Pasin, Paulo Verissimo. SCFS: a Shared Cloud-backed File System. USENIX’14: USENIX Annual Technical Conference. Philadelphia, USA. June 2014. pdf.

Alysson Bessani, João Sousa, Eduardo Alchieri. State Machine Replication for the Masses with BFT-SMaRt. DSN'14: The IEEE/IFIP International Conference on Dependable Systems and Networks. Atlanta, USA. June 2014. pdf (extended version) software.

Alysson Bessani, Marcel Santos, João Felix, Nuno Neves, Miguel Correia. On the Efficiency of Durable State Machine Replication. USENIX’13: USENIX Annual Technical Conference. San Jose, CA, USA. June 2013. pdf.

Miguel Garcia, Alysson Bessani, Ilir Gashi, Nuno Neves, Rafael Obelheiro. Analysis of operating system diversity for intrusion tolerance. Software: Practice and Experience. Willey. January 2014. pdf (A preliminar version appeared on DSN’11).

Alysson Bessani, Miguel Correia, Bruno Quaresma, Fernando André, Paulo Sousa. DepSky: Dependable and Secure Storage in a Cloud-of-Clouds. ACM Transactions on Storage. Vol. 9, Num. 4. ACM. November 2013. pdf (A preliminary version appeared on EuroSys’11) software.

Giuliana Veronese, Miguel Correia, Alysson Bessani, Lau Lung, Paulo Verissimo. Efficient Byzantine Fault Tolerance. IEEE Transactions on Computers. Vol. 62, Num. 1, pp. 16-30. IEEE Computer Society. January 2013. pdf (A supplement with correctness proofs is also available).

Paulo Sousa, Alysson Neves Bessani, Miguel Correia, Nuno Ferreira Neves, Paulo Verissimo. Highly Available Intrusion-Tolerant Services with Proactive-Reactive Recovery. IEEE Transactions on Parallel and Distributed Systems. IEEE Computer Society. April 2010 (vol. 21, no. 4), pp. 452-465. pdf (A preliminary version appeared on IEEE PRDC'07).

Giuliana Santos Veronese, Miguel Correia, Alysson Neves Bessani, Lau Cheuk Lung. Spin One's Wheels? Byzantine Fault Tolerance with a Spinning Primary. SRDS'09: The 30th IEEE Symposium on Reliable Distributed Systems. Niagara Falls, USA, September 2009. pdf.

Alysson Neves Bessani, Miguel Correia, Joni da Silva Fraga, Lau Cheuk Lung. Sharing Memory between Byzantine Processes using Policy-Enforced Tuple Spaces. IEEE Transactions on Parallel and Distributed Systems. IEEE Computer Society. March 2009 (vol. 20 no. 3) pp. 419-43. pdf (A preliminary version appeared on ICDCS'06).

Alysson Neves Bessani, Eduardo Adilio Pelinson Alchieri, Miguel Correia, Joni da Silva Fraga. DepSpace: A Byzantine Fault-Tolerant Coordination Service. EuroSys'08: The 3rd ACM SIGOPS/EuroSys European Systems Conference. Glasgow, Scotland. April 2008. pdf.


Ongoing: DiSIEM (EU H2020), IRCoC (FCT), Abyss (FCT, with IST/INESC-ID)

Past: SUPERCLOUD (EU H2020), SeGRID (EU FP7), BiobankCloud (EU FP7), SecFuNet (ICT EU-BR), RC-Clouds (FCT), SITAN (FCT), TCLOUDS (EU FP7 IP), MASSIF (EU FP7 IP), ReD (FCT), ReGenesys (FCT), CloudFIT (FCT), Diverse (FCT), CRUTIAL (EU FP7 STREP), Forever (EU/RESIST NoE)

BFT-SMaRt (a BFT/CFT state machine replication)

Current Students

PhD Students: Miguel Garcia (PhD, FCUL, Co-advised with Nuno Neves), Vinicius Cogo (PhD, FCUL), Fernando Alves (PhD, FCUL, Co-advised with Pedro Ferreira), Adriano Serckumecka (PhD, FCUL, Co-advised with Ibéria Medeiros), Tulio Ribeiro (PhD, FCUL)

MsC Students: Nuno Dionísio (Co-advised with Pedro Ferreira), Rui Azevedo (Co-advised with Ibéria Medeiros), Tomás Peixinho (Co-advised with Fernando Ramos), André Oliveira, Robin Vassantlal.

Research Staff: João Sousa, Ricardo Mendes, Tiago Oliveira, Eric Vial.

Past Students

João Sousa (PhD 2017, DI-FCUL), now a post-doc associate at LaSIGE, Portugal.

Luís Brandão (PhD 2015, ECE CMU/FCUL, Co-advised with Nicolas Christin), now at NIST, USA.

Eduardo Alchieri (PhD 2011, DAS UFSC-Brazil, Co-advised with Joni da Silva Fraga), now at UNB, Brazil.

Many master students... to be updated someday :-)


Informatics Engineering
Distributed Systems (Fall 2007-2012, 2018)
Security (Spring 2008, 2009, 2012-2, 2013)
Computer Systems Architecture (Fall 2014-2016)
Informatics Security (Spring 2008, 2009, 2012)

CMU-Portugal Masters in Information Security
Intrusion Tolerance (Spring 2010, 2011)

Masters in Informatics/Informatics Engineering/Informatics Security
Distributed Systems Programming (Fall 2010, 2017)
Software Security (Fall 2012)
Security Technologies (Spring 2013)
Fault-Tolerant Distributed Systems (Fall 2014-2018)
Intrusion Detection and Tolerance/Intrusion Tolerance (Spring 2014-2018)
Cloud Computing (Spring 2017-2018)

Information Technology
Distributed Applications (Fall 2008, 2009, Spring 2015-2018)
Informatics Security (2007/2008-2, 2008/2009-2)


In my free time I enjoy a lot of things such as sailing, surfing, running, videogames and reading.

Last Updated at Sep 24, 2018.