Dagstuhl Seminar Report: Security and Dependability for

Federated Cloud Platforms, 2012

Alexander ShraerGoogle, Inc.

shralex@google.com

Rudiger KapitzaTU Braunschweig

rrkapitz@ibr.cs.tu-bs.de

The Security and Dependability for FederatedCloud Platforms seminar [3] was held in SchlossDagstuhl1, July 8-13, 2012. Schloss Dagstuhl,also known as the Leibniz-Zentrum fur Infor-matik, is a renovated castle located in the sceniccountryside of Saarland, Germany. Dagstuhl of-fers a unique concept: 30-45 participants, all ofwhom receive invitations from Dagstuhl on be-half of the organizers, stay in the castle duringthe seminar (typically 3-5 days) enjoying all thatthe castle has to offer. Amongst other things thisincludes an impressive library, a music room fullof musical instruments, an excellent restaurant,as well as a wine cellar where a variety of cheese,wine and local beer is available daily for the late-evening social meetings.

The organizers of our seminar MatthiasSchunter, Marc Shapiro, Paulo Verissimo andMichael Waidner targeted a four day event andgathered a mixed group of senior, establishedand promising young researches from all overthe world. The program of the seminar wasnot set in advance, but most participants pro-vided an abstract [3] and gave short talks onrecent or ongoing work. The main purpose ofthese talks was generating discussion and col-laboration among the participants. During some

1http://www.dagstuhl.de/en/

of the evenings, researchers formed work-groupsand continued heated discussions fueled by wine,beer and cheese. For the younger participants,this was also a great opportunity to meet andget to know senior researchers in a very informalatmosphere – an opportunity that very few con-ferences can offer. To further foster the exchangeof ideas, in addition to intense research sessionseach seminar typically includes a group hike oran excursion. In our case, this included a rivercruise and a visit to a local brewery. Many ofthe participants, and we are among them, foundthe seminar to be one of the most productiveacademic events they experienced so far.

The seminar targeted the management andprotection of individual clouds and addressedthe trend towards cloud federation by bringingtogether researchers from security, dependabil-ity and systems management. The idea wasthat only such an integrated approach is ableto guarantee security and dependability whilepreserving the essential cost and efficiency bene-fits of today’s emerging solutions. The challengeto address was how to provide secure and de-pendable services on such federated cloud plat-forms. Selected research questions were: Howcan clouds securely interoperate, how can ser-vice availability be guaranteed despite failures orattacks on individual clouds, how can existing al-

gorithms be adjusted to provide scalable consis-tency guarantees, and finally whether cloud-of-cloud infrastructures can provide such benefitsat costs that are competitive with single cloudsolutions. While these questions were addressedduring the seminar it also became clear that re-search on the dependability and security of indi-vidual clouds remains an active and challengingarea, and therefore was also discussed in depth.

The article that follows [1] is a result of oneof the work-groups formed in the seminar. Thegroup included Distributed Systems and Secu-rity researchers with very diverse views and focusareas. As a result, the article, named ”VerifyingCloud Services: Present and Future”, covers thetopic from a wide range of perspectives, while atthe same time offers a common framework andclassification of the issues into four different ar-eas: 1) verification of service identity; 2) verifi-cation of service functional correctness; 3) veri-fication of service performance and dependabil-ity, and 4) verification of security policies. Theauthors believe that the collaboration, which in-cluded researchers from six countries and repre-sentatives from academia, research labs and in-dustry, could not have been possible in any other

setting, and would like to thank Schloss Dagstuhland the organizers of the seminar for this uniqueopportunity. Other works and new collabora-tions have emerged from discussions that startedduring the seminar, such as a recent study ofthe inherent properties of multi-cloud replicationand their dependence on the interface providedby individual cloud storage services [2].

References

[1] S. Bouchenak, G. Chockler, H. Chockler,G. Gheorghe, N. Santos, and A. Shraer. Veri-fying cloud services: Present and future. Op-erating Systems Review, 48, 2013.

[2] G. Chockler, D. Dobre, and A. Shraer.Consistency and complexity tradeoffsfor highly-available multi-cloud store.http://people.csail.mit.edu/grishac/mcstore.pdf,2013.

[3] Rudiger Kapitza, M. Schunter, M. Shapiro,P. Verissimo, and M. Waidner. Security andDependability for Federated Cloud Platforms(Dagstuhl Seminar 12281). Dagstuhl Reports,2(7):56–72, 2012.