High Performance, Robust and Secure Group Communication

About us
Technology Transfer
Secure Spread

Quarterly Technical Report, January 2001


During the past three months we continued our work on the Secure Spread System. We released Secure Spread Version 0 in November. We have completed the implementation of a robust contributory key agreement protocol based on Group Diffie Helman CLIQUES and we implemented in the Secure Spread Version 1 system. Currently this is going through testing and evaluation. Based on the results we obtained, we discovered some performance weaknesses with the current algorithms. In parallel with finalizing a release version of Secure Spread Version 1, we are exploring the computation and networking tradeoffs of a new, tree-based protocol to aleviate some of these weaknesses.

We have completed the design and development of a many-to-many flow control algorithm for wide area multicast. We have done validation experiments using ns2 as well as several actual experiments using the CAIRN network. This work is now augmented by developing a congestion control protocol for the wide area network dissemination.

We are continuing to define the necessary services for practical secure group comunication in particular and for overlay networks in general. We look beyond the key agreement protocols into authentication and access control.


Exploring Robusteness in Group Key Agreement
ps, ps.gz, pdf. Technical Report CNDS-2000-4.

Yair Amir, Yongdae Kim, Cristina Nita-Rotaru, John Schultz, Jonathan Stanton, and Gene Tsudik

In this paper we present two robust contributory key agreement protocols which are resilient to any sequence of events while preserving the group communication membership and ordering guarantees. This work will be presented in April in the coming IEEE IC-DCS 2001.


We have released Secure Spread Beta 0 in November. This is a preliminary version which includes a pretty stable API and a correct implementation of the CLIQUES key agreement protocol. The only weakness of this version is that its lack of support of cascading failures. This version is available for other researchers to use. It works with Spread 3.12, 3.13 and 3.14.

We have released Spread 3.14 in October. This was mainly a bug-fix version intended to support the growing practical utilization of Spread.

Technology Transfer:

We know of one Dynamic Coaltions project that already uses our software: This is the Efficient and Scalable Infrastructure Support project done at Johns Hopkins and Brown, which aims to provide scalable certification service. We are exploring potentail collaboration with other projects in the program.

Plans for Next Quarter:

  • Releasing Secure Spread Version 1 - a completely robust package that can handle any combination of network and user events.
  • Investigating practical authentication and access control for group communication in particular and overlay networks in general.
  • Continued research into high performance wide area group communication.

Questions or comments to:
webmaster (at) dsn.jhu.edu
TEL: (410) 516-5562
FAX: (410) 516-6134
Distributed Systems and Networks Lab
Computer Science Department
Johns Hopkins University
3400 N. Charles Street Baltimore, MD 21218-2686