Reuse It Or Lose It: More Efficient Secure Computation Through Reuse of Encrypted Values

Two-party secure function evaluation (SFE) has become significantly more feasible, even on resource-constrained devices, because of advances in server-aided computation systems. However, there are still bottlenecks, particularly in the input validation stage of a computation. Moreover, SFE research has not yet devoted sufficient attention to the important problem of retaining state after a computation has been performed so that expensive processing does not have to be repeated if a similar computation is done again. This paper presents PartialGC, an SFE system that allows the reuse of encrypted values generated during a garbled-circuit computation. We show that using PartialGC can reduce computation time by as much as 96% and bandwidth by as much as 98% in comparison with previous outsourcing schemes for secure computation. We demonstrate the feasibility of our approach with two sets of experiments, one in which the garbled circuit is evaluated on a mobile device and one in which it is evaluated on a server. We also use PartialGC to build a privacy-preserving "friend finder" application for Android. The reuse of previous inputs to allow stateful evaluation represents a new way of looking at SFE and further reduces computational barriers.Comment: 20 pages, shorter conference version published in Proceedings of the 2014 ACM SIGSAC Conference on Computer and Communications Security, Pages 582-596, ACM New York, NY, US

Women in the Quaker Community: The Richardson Family of Newcastle, C.1815-60

The town of Newcastle in the early nineteenth century offered many diverse forms of entertainment and socialising for middle class men and women. Although the religious beliefs of Quakers excluded them from sharing in many of these activities, their faith offered them unique opportunities to participate in, lead, and challenge middle class lifestyle. Through examining the domestic, religious, and charitable conduct of the women of the Richardson family it can be seen how their understanding of society was mediated through religious beliefs that allowed them to challenge the role of the typical middle class woman

Type Theory

The concept of type and typology are at the heart of Architecture. Type is the simple act of drawing similarity and difference between a group of artifacts. Typology, on the other hand, is a bit more complicated. When one engages with typology, they are taking the information they gather from observing the artifacts and transposing it into a new context. Most designers and architects refer to this act as type/typology. The distinction between the two terms is necessary for my work. My work looks at the relationship between these two events. As a collective they are Type Theory. With the emphasis of my work on Type Theory I set out to see if it was possible to translate type and typology into an open-ended process allowing variation and adaptability to occur. I looked at the various works to see if I could draw similarity and difference between them. I discovered that similarity and difference do in fact exist but not on the surface level. One must dig beneath the surface and look at the complex logical arguments each of the authors employ. By looking at the logical operations each author used I was able to put together a catalogue of different operations. These operations appeared to be the essence of a given work. Each author deployed these operations in some combination or another to construct their view of type and typology. I found that the operations act as a filtering device for our perceptions. And this act of filtering (creating a unique disposition) occurs all over the discourse. Actively changing the way we see and perceive things is just a part of design as it is to know technical skills. Since the operations are what determine a particular stance on type and typology I could, in theory, explore different combinations of these operations and see what kind of perspective they offer. I have only begun to touch the surface of this methodology. Supervisor: Steve Hard