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RITAS is a toolkit of intrusion-tolerant randomized agreement protocols implemented by Henrique Moniz in his Master and PhD work, advised by Nuno Neves and myself. RITAS is also the name of the project in the context of which the toolkit was developed.

RITAS provides two randomized binary consensus algorithms, echo broadcast, reliable broadcast, multi-valued consensus, vector consensus and atomic broadcast.


source code

This source code is provided as-is. It is only a prototype, there is no manual and support is in a best-effort basis. The code is available here.



Miguel Correia, Nuno F. Neves, Paulo Veríssimo. From Consensus to Atomic Broadcast: Time-Free Byzantine-Resistant Protocols without Signatures. Computer Journal. vol. 41, n. 1, pp 82-96, January 2006 (abstract) (pdf)

    Presents the original stack of protocols. There were a few modifications in the actual implementation.

H. Moniz and N. F. Neves and M. Correia and P. Veríssimo. Randomized Intrusion-Tolerant Asynchronous Services. In Proceedings of the International Conference on Dependable Systems and Networks (DSN), pages 568-577, June 2006. (pdf)

    Presents the stack and its experimental evaluation in a LAN.

H. Moniz and N. F. Neves and M. Correia and P. Veríssimo. Experimental Comparison of Local and Shared Coin Randomized Consensus Protocols. In Proceedings of the 27th IEEE Symposium on Reliable Distributed Systems. pages 235-244, Leeds, UK, October 2006 (pdf)

    Presents an experimental comparison of the two randomized binary consensus algorithms implemented, one using a shared coin and the other local coins.

Henrique Moniz, Nuno Ferreira Neves, Miguel Correia, António Casimiro, Paulo Verissimo. Intrusion Tolerance in Wireless Environments: An Experimental Evaluation. In Proceedings of the 13th IEEE Pacific Rim Dependable Computing Conference, pages 357-364. December 2007 (pdf)

    An experimental evaluation of the stack ported to mobile devices and in wireless networks.

H. Moniz and N. F. Neves and M. Correia and P. Veríssimo. RITAS: Services for Randomized Intrusion Tolerance. IEEE Transactions on Dependable and Secure Computing. (pdf)

    An extended version of the DSN'06 paper that includes experimental measurements in WANs (PlanetLab).

Henrique Moniz, Randomized Intrusion-Tolerant Asynchronous Services, Master / Mestrado em Informática, Faculdade de Ciências da Universidade de Lisboa, December 2006. (pdf)

    Includes a full description of the implemented protocols.

Henrique Moniz, Byzantine Fault-Tolerant Agreement Protocols for Wireless Ad hoc Networks, PhD Thesis, Faculdade de Ciências da Universidade de Lisboa, 2010.

    Comparison of the consensus protocols, in WANs and wireless networks.

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