Building reliable and secure distributed systems is today too costly. This is bad because it results in systems that can easily be hacked, for example current voting systems. I believe that interactive formal verification, with robust automation like in Ivy, is the right tool for the job. We have shown that the notoriously complex consensus algorithms are in fact easy to verify with Ivy. I am currently working on extending the approach to more diverse classes of systems.
One specific problem I am currently interested in is the formal verification of the synchronizers used in partially synchronous approaches to solving consensus. Synchronizers rely on real-time properties that are hard to model in the Ivy verification approach.
I work at Galois, Inc. Portland, Oregon.
Marta Lokhava, Giuliano Losa, David Mazières, Graydon Hoare, Nicolas Barry, Eliezer Gafni, Jonathan Jove, Rafał Malinowsky, Jed McCaleb. Fast and secure global payments with Stellar, SOSP 2019.
Giuliano Losa, Eli Gafni, and David Mazières. Stellar Consensus by Instantiation, DISC 2019. Extended Version and additional material.
Idan Berkovits, Marijana Lazic, Giuliano Losa, Oded Padon, Sharon Shoham. Verification of Threshold-Based Distributed Algorithms by Decomposition to Decidable Logics. CAV 2019. Extended version
Eli Daian, Giuliano Losa, Yehuda Afek and Eli Gafni. Deterministic Objects Give Life to Non-Deterministic 1-Consensus Tasks, DISC 2018 (also see this github repository).
Marcelo Taube, Giuliano Losa, Kenneth McMillan, Oded Padon, Mooly Sagiv, Sharon Shoham, James R. Wilcox, and Doug Woos: Modularity for Decidability of Deductive Verification with Applications to Distributed Systems, PLDI 2018. Additional material here.
Oded Padon, Jochen Hoenicke, Giuliano Losa, Andreas Podelski, Mooly Sagiv, and Sharon Shoham: Reducing Liveness to Safety in First-Order Logic, POPL 2018.
Carole Delporte-Gallet, Hugues Fauconnier, Eli Gafni, Giuliano Losa: The assignment problem, ICDCN 2018. Technical report and TLA+ specifications.
Oded Padon, Giuliano Losa, Mooly Sagiv, and Sharon Shoham: Paxos Made EPR: Decidable Reasoning about Distributed Consensus, OOPSLA 2017. Technical report on arXiv.org and paper site at TAU with supplementary material.
Balaji Arun, Sebastiano Peluso, Roberto Palmieri, Giuliano Losa, and Binoy Ravindran: Speeding up Consensus by Chasing Fast Decisions. 47th Annual IEEE/IFIP International Conference on Dependable Systems and Networks, DSN, June 26-29, 2017, Denver, CO, USA. Technical report.
Giuliano Losa, Sebastiano Peluso, Binoy Ravindran: Brief Announcement: A Family of Leaderless Generalized-Consensus Algorithms, PODC 2016. PDF and TLA+ specifications.
Sebastiano Peluso, Alexandru Turcu, Roberto Palmieri, Giuliano Losa, Binoy Ravindran: Making Fast Consensus Generally Faster, DSN 2016. PDF and TLA+ specifications.